Nozzle head, nozzle head holder, and droplet jet patterning device

ABSTRACT

First link members ( 56 A and  56 B), a pair of second link members ( 57 A and  57 B), and three head holders ( 51 R,  51 G, and  51 B) are installed rotatably. Rotational pivots ( 50 A and  50 B) provided at intermediate portions of the second link members ( 57 A and  57 B) and a reference nozzle of the reference head holder ( 51 R) are positioned on the same line in a main scanning direction. The reference head holder ( 51 R) is rotated about the reference nozzle, and the other head holders ( 51 G and  51 B) are also rotated simultaneously. The head holders ( 51 G and  51 B) are formed to be movable parallel to a sub scanning direction, irrespective of the rotation angles thereof.

This application is a division of Ser. No. 10/491,123 filed Mar. 26,2004 now U.S. Pat. No. 7,008,428, which is herein incorporated byreference.

TECHNICAL FIELD

The present invention relates to a nozzle head holder and, inparticular, to a nozzle head holder in which the nozzle pitch can beadjusted in a sub scanning direction and also the nozzle head positioncan be adjusted minutely in the sub scanning direction, and a dropletjet patterning device provided with the same.

BACKGROUND OF ART

Recently, as the use of inkjet printers of various configurations hasspread widely, color inkjet printers that are capable of high-resolutioncolor printing at substantially photographic quality have becomepopular. In an inkjet printer, a plurality of nozzle heads, each ofwhich having a number (such as 128) of minute nozzles formed in one or aplurality of rows in the sub scanning direction, are mounted in acarriage. A dot pattern is formed on a discharge-target medium bydischarging ink droplets from each nozzle, thus recording a desiredimage. Japanese Patent Application Laid-Open No. 11-334049 discloses atechnique of varying the nozzle pitch by causing a movable link to movewith respect to a fixed link, to rotate the nozzle heads partly.

In recent years, liquid-crystal displays have become common in personalcomputers, wordprocessors, copiers, fax machines, mobile phones, andvarious types of portable terminal. In addition, liquid-crystal displaysthat are capable of color display have recently been widely adopted. Acolor filter is used in the color display of a liquid-crystal display. Acolor filter is formed of a regular dot pattern of fine filter pixels inthe three primary colors of light (red (R), green (G), and blue (B)) ona transparent film. The color filter can be formed by a droplet jetpatterning device having a configuration similar to that of the aboveinkjet printer.

A droplet jet patterning device for manufacturing such a color filter isdisclosed in Japanese Patent No. 3,121,226. This device is designed todischarge droplets of the three colors R, G, and B from a plurality ofnozzles formed in a nozzle head, to record R, G, and B dot patterns on aglass substrate. The nozzle pitch can be adjusted to be suitably smallerthan the actual nozzle pitch in the sub scanning direction by incliningthe nozzle head with respect to the sub scanning direction. When thenozzle head is inclined, the discharge timing of each nozzle is madedifferent to align the positions of the recording start edge on theglass substrate. Deviations of each nozzle from the center line of thenozzle array are corrected by controlling the discharge timing.

A droplet jet patterning device for manufacturing a color filter isdisclosed in Japanese Patent Application Laid-Open No. 9-300664. In thiscase, the nozzle head is inclined and also the nozzle head is moved inthe sub scanning direction. This device is provided with nozzle headsfor the three colors R, G, and B that are formed in a plate. Each nozzlehead is held in a state perpendicular to the discharge-target medium.The two ends of each nozzle head are supported in holders, with theholder at one end being connected rotatably to a head mount and theholder at the other end being connected rotatably to a slide member.Each nozzle head is urged toward the head mount side by a coil spring,so that the relative position of each nozzle head with respect to thehead mount can be adjusted by using screws. If fine screws for slidemembers are used to move the slide members in the sub scanningdirection, the inclination angle of the nozzle heads with respect to thesub scanning direction can be changed so that the dot pitch can beadjusted in the sub scanning direction.

Organic electroluminescent (EL) displays are gradually becomingpracticable as the next generation of displays instead of liquid-crystaldisplays. An EL substrate for an organic EL display has an anode layer,a hole transport layer, a light-emitting layer, and a cathode layerformed on the surface of a glass substrate, by way of example. Variouslight-emitting organic compounds corresponding to light-emission colorsare used in the light-emitting layer. An organic EL display has a simpleconfiguration and can be made thinner, lighter, and less expensive, andit also has advantage such as little dependency on the angle of viewingand a lower power consumption.

The method of manufacturing an EL substrate for a color organic ELdisplay will be briefly described here. Above an anode layer formed on aglass substrate, droplets for forming a hole transport layer aredischarged and are then fixed by heating in a vacuum or an inert gas.Three different types of droplet corresponding to R, G, and B for an ELlight-emitting layer are then discharged onto the hole transport layerto form a regular dot pattern of three colors of light-emitting pixels.After the dot pattern has been heated in a vacuum, a cathode layer isformed over the EL light-emitting layer.

However, the above-described prior art has problems, as described below.First of all, since the inkjet printer of Japanese Patent ApplicationLaid-Open No. 11-334049 has a configuration in which movable links aremoved with respect to fixed links to incline the nozzle head itself, itis necessary to combine at least the fixed links, the movable links, andthe nozzle head into a head mount to maintain the inclination angle.This configuration is complicated because the movable links move in anarc shape with respect to the fixed links. Therefore, it is difficult tomanufacture a nozzle head unit with nozzle heads.

Japanese Patent No. 3,121,226 does not disclose any mechanism forsupporting the nozzle head in an inclinable manner with respect to thesub scanning direction and the actuator for causing the rotation of thenozzle head. Japanese Patent No. 3,121,226 does not propose a techniquefor enabling removal of a plurality of nozzle heads as a nozzle headunit. The center of rotation during the inclination of the nozzle headis also not clear.

Since the droplet jet patterning device of Japanese Patent ApplicationLaid-Open No. 9-300664 is provided with a plate-shaped nozzle head thatstands vertically, there are large limitations on the shape of thenozzle head. During maintenance or replacement of the nozzle heads, eachnozzle head must be removed from the holders. However, it would bedifficult to set the vertical position of the nozzle head precisely whenthe two ends of the nozzle head can be inserted and removed from abovewith respect to the holders. If each nozzle head cannot be inserted andremoved from above the holders, it is difficult to remove the nozzlehead and thus maintainability cannot be ensured.

Moreover, since the center of rotation of each nozzle head is therotational axis for supporting the holders, if the nozzle heads arepartly rotated, all of the nozzles will change positions in both themain scanning direction and the sub scanning direction Y. For thatreason, the data processing load is increased during the calculation ofthe recording drive data and a rotational angle for causing relativemovement of the glass substrate with respect to the nozzle heads in themain scanning direction and the sub scanning direction, making itdifficult to increase the precision of the pattern formation.

In addition, since the movement of the slide members is done by manuallyoperating fine screws, the maximum inclination angle of the nozzle headscannot be made so large. Accordingly, the width of variation of the dotpitch is small.

It often happens in the droplet jet patterning device that dots of aspecific color (such as R dots) are displaced by a small distance fromeach of other dots (such as G or B dots) in the sub scanning direction,as shown in FIG. 29( c). In such a case, it is useful if each nozzlehead is moved by just a predetermined distance in the sub scanningdirection. However, the configuration of Japanese Patent ApplicationLaid-Open No. 9-300664 enables fine movements of each nozzle head onlyin the lengthwise direction (nozzle array direction) of the nozzle head,making it impossible to move the nozzle head parallel to the subscanning direction when the nozzle head is inclined with respect to thesub scanning direction. Since the calculation of the amount of finemovement in the sub scanning direction must be based on both the amountof movement due to the tangent screws and the inclination angle of thenozzle heads, the data processing load is increased during the obtainingof the recording drive data and the inclination rotational angle, makingit difficult to increase the precision of pattern formation.

Furthermore, since the nozzle heads are returned in a parallel postureto the sub scanning direction and then the positions of the nozzle headsin the sub scanning direction must be minutely adjusted, the operationof the tangent screws is complicated. Since the positions of the tangentscrews and the inclination state will vary with the inclination angle ofthe nozzle heads, a configuration in which the tangent screws are drivenautomatically would be totally impossible.

Thus an objective of the present invention is to provide a nozzle headholder in which the insertion and removal of nozzle heads is simple, andwhich enables the simple insertion to and removal from the device itselfwith the nozzle heads still installed.

Another objective of the present invention is to provide a nozzle headholder in which the rotatable angle of the nozzle heads is large and inwhich the nozzle heads can be moved parallel to the sub scanningdirection, irrespective of the rotation angle of the nozzle heads.

A further objective of the present invention is to provide a droplet jetpatterning device in which the above nozzle head holder is installed anda nozzle head that can be installed to such a nozzle head holder.

DISCLOSURE OF INVENTION

In order to solve the above-described problems, a nozzle head holderaccording to the present invention is characterized by holding aplurality of nozzle heads having a plurality of nozzles. Each nozzlehead is disposed at a predetermined spacing in a main scanningdirection. The nozzle head holder includes a four-bar linkage having apair of first link members that extend parallel to the main scanningdirection and a pair of second link members that connect the pair offirst link members; and movement means for causing at least one nozzlehead of the plurality of nozzle heads to move parallel to a sub scanningdirection that is perpendicular to the main scanning direction. The twoend portions of each of the nozzle heads are connected to the pair offirst link members, respectively. The movement means causes the at leastone of the nozzle heads to move parallel in the sub scanning direction(Y), relative to the pair of first link members.

Since this configuration ensures that at least one nozzle head of theplurality of nozzle heads can move parallel to the sub scanningdirection with respect to the pair of first link members, the nozzleheads can be moved minutely in the sub scanning direction to finelyadjust the positions of the nozzle heads in the sub scanning direction,irrespective of the rotation angle of the nozzle heads. The abovestructure makes it possible to perform accurate and efficient fineadjustments of the nozzle heads when it is necessary to finely adjustthe positions in the sub scanning direction of the nozzle head for G andthe nozzle head for B with respect to the nozzle head for R, inaccordance with the disposition of pixels formed of three recording dotsin R, G, and B, by way of example.

In addition, since a plurality of nozzle heads are provided, it ispossible to form a pattern by discharging droplets of a plurality oftypes, when a color filter or color EL substrate is manufactured, by wayof example.

Since this nozzle head holder is provided with the four-bar linkage, thepair of rotational pivots, and the nozzle heads having two end portionsthat are connected rotatably to the pair of first link members,respectively. The configuration of the nozzle head holder can be madesimple. The configuration for removing and attaching the nozzle headsfor repair or replacement can also be simplified, making it possible toensure maintainability.

Since the four-bar linkage itself can be configured of high-precisioncomponents and the nozzle heads can be mounted highly precisely in thisfour-bar linkage, it is possible to manufacture a highly precise nozzlehead holder that minimizes manufacturing errors.

It is preferable that concavities having guide surfaces are formed inthe pair of first link members, respectively. The movement means areprovided with a pair of roller members that are installed rotatably onthe two end portions of the at least one of the nozzle heads, andpressure members that press the roller members against the guidesurfaces. And the pressure members are moved parallel to the subscanning direction along the guide surfaces, while the roller membersare pressed against the guide surfaces.

This configuration makes it possible to move the nozzle heads finelyparallel to the sub scanning direction, through the guide surfaces andthe pair of roller members, even when the nozzle heads are in arotational posture. In addition, since the pair of roller members areeach positioned at fixed positions with respect to the pair of firstlink members, irrespective of the magnitude of the rotational angle ofthe nozzle heads, the movement mechanisms can be mounted at fixedpositions of the first link members, and actuators for moving thesemovement mechanisms can be provided externally, so that fine adjustmentof the nozzle heads in the sub scanning direction can be automated.

Preferably, the plurality of nozzle heads can be installed removably onthe pair of first link members. This structure simplifies repair orreplacement of the nozzle heads, improving maintainability.

The two end portions of each of the nozzle heads may be urged by aresilient member so as to be in surface-contact with upper surfaces ofthe first link members. If the two end portions of each nozzle head arein surface-contact with the first link members, errors in the heightwisepositions of the nozzle heads in the vertical direction are minimized,and the height of the nozzle heads with respect to the discharge-targetmedium can be set precisely. Therefore, the performance of the dischargerecording is increased.

Preferably, each of the nozzle heads is provided with a nozzle portionhaving a plurality of nozzles formed therein, and a head holder forsupporting the nozzle portion. The two end portions of the head holderare connected to the pair of first link members, respectively.

A nozzle head according to the present invention is characterized inbeing used in the above-described nozzle head holder. In this nozzlehead, a plurality of fine-diameter nozzles are formed in a row in thesub scanning direction, by way of example. Preferably, the pitch betweenthese nozzles can be set to a dimension such as 75 dpi or 150 dpi. Apair of roller members can be provided for connecting the two ends ofthis nozzle head to the first link members in a rotatable manner,respectively. Since the roller members can rotate with respect to thenozzle head, smooth movement can be obtained by the rotation of theroller members during the rotation of the nozzle head as well as duringthe parallel movement of the nozzle head to the sub scanning directionin the inclined state.

A droplet jet patterning device according to the present inventionincludes: the above-described nozzle head holder; a head assemblyattachment stand for installing the nozzle head holder in a removablemanner; a medium holder means for holding a discharge-target medium; arelative movement generation means for causing the discharge-targetmedium to move in a main scanning direction and a sub scanning directionrelative to the nozzle head; pivoting means for causing the four-barlinkage to pivot; and rotational pivots provided at intermediateportions of the pair of second link members. The pair of second linkmembers are capable of rotating about the rotational pivots. The two endportions of the nozzle head are connected rotatably to the pair of firstlink members, respectively. The pivoting means causes the pair of secondlink members to rotate about the rotational pivots to cause the four-barlinkage to pivot

Since this droplet jet patterning device is provided with the nozzlehead holder, the droplet jet patterning device has the similar effectsto those of that nozzle head holder. Before pattern formation, when thepair of second link members is rotated about the rotational pivots atthe intermediate portions thereof, the pair of second link membersrotate, the pair of first link members move in the main scanningdirection and also in opposite direction to each other. The two ends ofeach nozzle head connected to the pair of first link members are causedto move. The plurality of nozzle heads rotates with respect to the subscanning direction. By rotating the nozzle heads with respect to the subscanning direction, the discharge pitch in the sub scanning direction isadjusted finely, so that a desired discharge pitch is changed. And then,one pass of the discharge recording is done while the discharge-targetmedium is moved with respect to the nozzle head holder in the mainscanning direction. After that, the next pass of discharge recording isdone after a suitable relative movement of the discharge-target mediumin the sub scanning direction. Thus, the discharge recording is done byrepeating these operations sequentially.

Since the nozzle heads are rotated by causing the four-bar linkage topivot, the rotation angle of the nozzle heads can be increased, so thatit is possible to increase the width of variation of the discharge pitchin the sub scanning direction.

In this case, preferably, the droplet jet patterning device includes amovement drive means connected removably to the movement means fordriving the movement means to cause at least one nozzle head to moveparallel to the sub scanning direction. Accordingly, it is possible touse the movement drive means to cause the nozzle heads to move in thesub scanning direction through the movement mechanism, after the nozzlehead holder is mounted into the head assembly attachment stand and themovement drive means is connected to the movement mechanism, thusenabling automation.

Furthermore, preferably, the droplet jet patterning device furtherincludes rotational amount detection means for detecting the pivotingamount of the four-bar linkage, and rotational amount control means forcontrolling the pivoting means based on the detected amount of rotation.According to this configuration, it is possible to cause the four-barlinkage to pivot to any desired rotation angle, by detecting therotation angle by the rotational amount control means, then using thatrotational amount to control the pivoting means by the rotational amountcontrol means.

Another nozzle head holder according to the present invention is anozzle head holder for holding a nozzle head in which is formed aplurality of nozzles. The nozzle head holder includes: a four-barlinkage having a pair of first link members that extend parallel to amain scanning direction, and a pair of second link members that connectthe pair of first link members; and rotational pivots provided atintermediate portions of the pair of second link members. The pair ofsecond link members are capable of rotating about the rotational pivots.A tip end portion of the nozzle head is connected rotatably to one firstlink member, and a base end portion of the nozzle head is connectedrotatably to the other first link member.

When the pair of second link members of the above configuration isrotated about the rotational pivots at intermediate portions thereof,the pair of second link members rotate, the pair of first link membersmove in the main scanning direction and in the opposite directions toeach other. The two ends of each nozzle head connected to the pair offirst link members to rotate the plurality of nozzle heads with respectto the sub scanning direction. Since the nozzle heads are rotated bypivoting the four-bar linkage, the rotational angle of the nozzle headscan be increased, and the width of variation of the discharge pitch inthe sub scanning direction can be increased.

Since the above nozzle head holder is provided with the four-barlinkage, the pair of rotational pivots, and the nozzle heads having twoend portions that are connected rotatably to the pair of first linkmembers, the configuration of the nozzle head holder can be made simple.The configuration required for removing and attaching the nozzle headsfor repair or replacement can also be simplified, thereby ensuringmaintainability.

Since the four-bar linkage itself can be configured with high precisionand the nozzle heads can be mounted precisely in this four-bar linkage,it is possible to provide a precise nozzle head holder that minimizesmanufacturing errors.

The pair of rotational pivots is provided in intermediate portions ofthe pair of second link members and rotationally supported. Accordingly,the reference nozzle of the nozzle head (such as the No. 1 nozzle) canbe positioned on the line linking the pair of rotational pivots. Sincethis configuration ensures that the position of the reference nozzle(the position in the main scanning direction and the sub scanningdirection) does not change even if the nozzle heads rotate, dataprocessing can be simplified to generate the drive data, for relativemotion between the discharge-target medium and the nozzle head, therebyincreasing the precision of the pattern formation.

A plurality of nozzle heads can be disposed at a predetermined spacingin the main scanning direction on the pair of first link members.According to the above configuration, it is possible to rotate theplurality of nozzle heads with respect to the sub scanning direction toform the pattern, which is applicable to manufacture color filters andEL substrates for organic color EL displays.

Preferably, the plurality of nozzle heads discharges droplets of each ofa predetermined plurality of colors for forming EL light-emitting layersof the plurality of colors. This makes it possible to reduce the stepsfor forming the EL light-emitting layer, enabling an increase inthroughput and making it possible to manufacture EL substrates forfull-color use.

Preferably, the nozzle head discharges droplets for forming a holetransport layer for transporting holes within an EL light-emitting layerto cause the EL light-emitting layer to emit light. According to theabove configuration, it is possible to form a hole transport layer.

Preferably, a plurality of nozzles is formed in each of the nozzleheads. A reference nozzle which is the closest to the base of the nozzlehead among the plurality of nozzles formed in at least one nozzle headcan be positioned on a line linking the pair of rotational pivots.

Since the above structure ensures that the position of the referencenozzle in the sub scanning direction (the position in the main scanningdirection and the sub scanning direction) does not change even if thenozzle heads rotate, data processing can be simplified to generate thedrive data for causing relative motion between the discharge-targetmedium and the nozzle head, while increasing the precision of thepattern formation. In addition, since the nozzle heads are rotated bycausing the four-bar linkage to pivot, the rotation angle of the nozzleheads can be increased, thereby increasing the width of variation of thedischarge pitch in the sub scanning direction.

Preferably, the plurality of nozzle heads is installed removably on thepair of first link members. This simplifies the repair and replacementof the nozzle heads, improving maintainability.

Another nozzle head according to the present invention is characterizedby being used in the above described nozzle head holder. If connectionpins are provided for connecting the two ends of the nozzle head to thefirst link members in a rotatable manner, for example, the nozzle headscan be installed to and removed from the nozzle head holder with asimple configuration.

Another droplet jet patterning device according to the present inventionincludes a head assembly attachment stand for installing theabove-described nozzle head holder in a removable manner; a mediumholder means for holding a discharge-target medium; pivoting means forcausing a four-bar linkage to pivot; and relative movement means forcausing the discharge-target medium, which is held in the medium holdermeans, to move in a main scanning direction and a sub scanning directionrelative to the nozzle head.

Since this configuration ensures that the nozzle head holder isinstalled removably in the head assembly attachment stand, the nozzlehead holder can be attached and removed easily and repair or replacementof the nozzle heads can be done easily. Since the pivoting means isprovided that acts on the pair of rotational pivots of the four-barlinkage to cause the four-bar linkage to pivot, the four-bar linkage canbe pivoted rapidly, automatically, and precisely when the dischargepitch in the sub scanning direction is adjusted by a small distance. Inaddition, the discharge-target medium is supported by the medium holdermeans and the pattern formation can be done while relative movement isimplemented in both the main scanning direction and the sub scanningdirection between the discharge-target medium and the nozzle heads.

Preferably, the nozzle head holder is further provided with rotationangle detection means for detecting the pivoting amount of the four-barlinkage, and rotational amount control means for controlling thepivoting means based on the detected pivoting amount. Since the rotationangle detection means and the rotational amount control means areprovided in this configuration, it is possible to perform the rotationof the four-bar linkage, when the one or plurality of nozzle heads andthe pair of second link members of the four-bar linkage is rotated arepivoting.

Preferably, the rotation means includes a rotational actuator connectedto one second link member, where the rotational actuator causes the onesecond link member to rotate about one of the rotational pivots.According to this configuration, the rotational actuator is providedwith to cause the second link member about either one of the pair ofrotational pivots, the second link members, or the four-bar linkage canpivoting with a simple configuration. It is therefore possible to rotatethe nozzle head by means of the four-bar linkage rapidly, automatically,and precisely when the discharge pitch in the sub scanning direction isto be adjusted by a small amount.

Another droplet jet patterning device according to the present inventionis provided with a nozzle head having a plurality of nozzles formedalong a sub scanning direction perpendicular to a main scanningdirection, for discharging droplets from the plurality of nozzles toform a pattern on a discharge-target medium. The droplet jet patterningdevice includes a holder member for rotatably supporting the nozzlehead; rotational drive means for causing the nozzle head supported onthe holder member to rotate within a range of 0 to 60 degrees withrespect to the sub scanning direction about an axis of the referencenozzle, or an axis in the vicinity thereof; and rotation control meansfor controlling the rotational angle of the nozzle head by therotational drive means, based on a discharge resolution.

Since this configuration causes rotation of the nozzle head about theaxis of the reference nozzle or an axis in the vicinity thereof when thenozzle head is rotated, and thus position of the reference nozzle in thesub scanning direction and the main scanning direction does not changeor may change by a small amount, the data processing for creating thedrive data for recording can be simplified, the control for dischargerecording can be simplified, and the pattern formation can be done moreprecisely.

Since the nozzle heads can be rotated within the range of 0 to 60degrees, if the nozzle pitch is P and the inclination rotational angleis θ, the discharge pitch in the sub scanning direction (P×cos θ) can bevaried between P and 0.5P, making it possible to increase the width ofvariation of the discharge pitch in the sub scanning direction and setthe resolution in the sub scanning direction continuously within therange of P to 0.5P. Moreover, the provision of the rotational mechanism,the rotational drive means, and the rotation control means cause thenozzle heads to rotate automatically, without any manual operation,thereby setting the rotational angle of the nozzle heads rapidly andprecisely.

Preferably, the droplet jet patterning device further includes relativemovement means for causing the discharge-target medium to move in thesub scanning direction relative to the nozzle head and feed amountcontrol means for controlling the relative movement means on the basisof the discharge resolution so as to perform relative motion of thedischarge-target medium in the sub scanning direction by an interlacemethod.

Since the droplet jet patterning device is provided with the relativemovement means for causing the discharge-target medium to move in thesub scanning direction relative to the nozzle head and the feed amountcontrol means for controlling the relative movement means on the basisof the discharge resolution so as to perform relative motion in the subscanning direction by an interlace method, it is possible to set thefeed amount in the sub scanning direction automatically and relativelymove the discharge-target medium and the nozzle head automatically, toensure that the discharge pitch in the sub scanning direction is set toa pitch suitable for the discharge resolution. In addition, since thedischarge pitch in the sub scanning direction of the droplets dischargedonto the discharge-target medium can be varied over an even wider range,the discharge pitch can be adjusted dependently on the dischargeposition on the discharge-target medium (the discharge pattern)completely reliably.

Preferably, the holder member includes a pair of first link members thatextend parallel to the main scanning direction and a pair of second linkmembers that connect together the pair of first link members. The twoend portions of the nozzle head are connected rotatably to the pair offirst link members.

According to the above configuration, it is possible to cause the nozzlehead to rotate reliably within the range of 0 to 60 degrees. Moreover,this configuration ensure that the four-bar linkage itself is highlyprecise with few manufacturing errors. Additionally, the rotatableconnections of the two ends of the nozzle head to the pair of first linkmembers ensures that the precision of the nozzle head assembly and ofthe positioning during rotation can be maintained at high levels, thusmaking it possible to maintain high levels of precision in the patternformation.

Preferably, the holder member further includes rotational pivots forsupporting the pair of second link members at intermediate portionsthereof, wherein the pair of second link members are supported to rotateabout the rotational pivots.

According to this configuration, a reference nozzle which is the closestto the base of the nozzle head among the plurality of nozzles of thenozzle head is positioned on a line linking the pair of rotationalpivots. Since such a configuration ensures that the position of thereference nozzle (the position in the main scanning direction and theposition in the sub scanning direction) does not change even when thenozzle head is rotated, the data processing for calculating therotational angle and the data processing for the recording drive data issimplified, thereby increasing the precision of the pattern formation.

Preferably, the nozzle heads are disposed at a predetermined spacing inthe main scanning direction. According to this configuration, it ispossible to provide a droplet jet patterning device that is providedwith R, G, and B nozzle heads, by way of example. The droplet jetpatterning device can produce color filters or EL substrates for colororganic EL displays.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view of a droplet jet patterning device according toan embodiment of the present invention;

FIG. 2 is a plan view of the droplet jet patterning device;

FIG. 3 is a partially enlarged plan view of the droplet jet patterningdevice;

FIG. 4 is a partially enlarged front view of the droplet jet patterningdevice;

FIG. 5 is a plan view showing a glass substrate, the medium holdermoving device, and the substrate receptacle of the droplet jetpatterning device;

FIG. 6 is an illustration of the raised position of the head portion ofthe droplet jet patterning device;

FIG. 7 is a plan view of part of the Z-axis slider, the nozzle headholder, the rotational drive mechanism, and the encoder of the dropletjet patterning device;

FIG. 8 is a section (partially cutaway) taken along the line VIII-VIIIof FIG. 7;

FIG. 9 is a partially cutaway longitudinal right side view of the nozzlehead holder, the rotational drive mechanism, and the encoder;

FIG. 10 is a partially cutaway longitudinal left side view of the nozzlehead holder;

FIG. 11 is an end view (including a partially cutaway longitudinalportion) taken along the line XI-XI of FIG. 7;

FIG. 12 is a longitudinal section through essential components in astate in which the nozzle head holder is installed on the supportingsubstrate;

FIG. 13 is a longitudinal section through essential components in astate in which the nozzle head holder is removed from the supportingsubstrate;

FIG. 14 is a partially cutaway transverse plan view of the nozzle headholder;

FIG. 15 is a back view of the nozzle head holder;

FIG. 16 is a longitudinal sectional side view of the nozzle head holder;

FIG. 17 is another longitudinal sectional side view of the nozzle headholder;

FIG. 18 is a partially cutaway longitudinal front view of the nozzlehead holder;

FIG. 19 is a schematic plan view of the nozzle head holder;

FIG. 20 is a plan view of essential components of the rotational drivemechanism for causing the second link members to rotate;

FIG. 21 is a transverse sectional side view of essential components ofthe guide mechanism and the moving mechanism of the nozzle head holder;

FIG. 22 is a plan view of the head holder;

FIG. 23 is a longitudinal sectional side view of essential components ofthe nozzle head holder;

FIG. 24 is an illustration of inter-nozzle dimension errors in thenozzle head;

FIG. 25 is a table showing rankings of inter-nozzle dimension errors andcentral errors;

FIG. 26 is a side view of the liquid supply mechanism;

FIG. 27( a) is a view of the four-bar linkage and the nozzle heads in aninitial position state;

FIG. 27( b) is a view of the four-bar linkage and the nozzle heads in arotating state;

FIG. 28 is an illustration of the configuration of the rotational drivemechanism, the encoder, and the position adjustment drive mechanism;

FIG. 29( a) is an illustration of an example of the disposition of R, G,and B dots;

FIG. 29( b) is an illustration of another example of the disposition ofR, G, and B dots;

FIG. 29( c) is an illustration of a further example of the dispositionof R, G, and B dots;

FIG. 30 is a block diagram of the configuration of the dischargeinspection mechanism;

FIG. 31 is an illustration of the CCD imaging area in the CCD cameraused for discharge inspection;

FIG. 32 is an illustration of an image of droplets and an observationwindow of FIG. 31;

FIG. 33 is a diagram of the configuration of the glass substrate on thesubstrate receptacle and the automatic alignment adjustment mechanism;

FIG. 34 is a perspective view of the head maintenance mechanism;

FIG. 35 is an illustration of relative movement between the glasssubstrate and the nozzle heads that form the discharge pattern ofdroplets in a plurality of pattern formation areas of a glass substrate;

FIG. 36 is an illustration of movement paths for forming a pattern bycausing the nozzle heads to move one pass at a time;

FIG. 37 is an illustration of movement paths for forming a pattern bymoving the nozzle heads in an interlaced manner;

FIG. 38 is part of a block diagram of the control system of the dropletjet patterning device;

FIG. 39 is the remainder of the block diagram of FIG. 38;

FIG. 40 is a flowchart of continuous recording control for dischargerecording on a glass substrate;

FIG. 41 is a flowchart of the recording preparation processing executedby the continuous recording control;

FIG. 42 is a flowchart of the inspection processing executed by thecontinuous recording control;

FIG. 43 is a continuation of the flowchart of FIG. 41;

FIG. 44 is a flowchart of the home-position return processing executedby the continuous recording control;

FIG. 45 is a flowchart of the waiting-position return processingexecuted by the continuous recording control;

FIG. 46 is a flowchart of the discharge inspection processing executedby the continuous recording control; and

FIG. 47 is a flowchart of R-head inspection processing executed by thedischarge inspection processing of FIG. 46.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention is described below with referenceto the accompanying drawings. Note that this embodiment relates to theapplication of the present invention to a droplet jet patterning devicefor manufacturing an EL substrate (a thin glass plate withlight-emitting layers of three colors (R, G, and B) formed thereon) thatis used in an organic EL (electro-luminescence) display.

As shown in FIG. 1, a droplet jet patterning device 1 is provided with abase frame 2, a parallelepiped-shaped casing 3, a medium holder movingdevice 5, a Z-axis slide mechanism 6, a nozzle head holder 7, a liquidsupply device 12, and a feed loader H. The droplet jet patterning device1 is further provided with an inspection/adjustment device 9 as shown inFIG. 2 and a control device 13 as shown in FIG. 38. As shown in FIG. 6,the nozzle head holder 7 is provided with a head portion 43, and aplurality of nozzle heads 8 for discharge recording is provided in thehead portion 43. The nozzle heads 8 discharge droplets of a plurality ofcolors to form a dot pattern on a glass substrate 4 that is a recordingmedium, thus forming EL light-emitting layers that emit light of aplurality of predetermined colors. The following description will bemade for explaining the above elements in turn.

As shown in FIG. 1, the casing 3 is formed above the base frame 2 andthe interior space of the casing 3 is partitioned by a horizontalpartitioning plate 14 (partition member) at an intermediate positioninto a first-floor patterning room 15 and a second-floor maintenanceroom 16. A pattern processing stage 120 is provided in the patterningroom 15 and an inspection processing stage 44 is provided in themaintenance room 16. An aperture portion 14 a (see FIG. 6) is formed inthe partitioning plate 14 to enable the passage of the nozzle headholder 7. The above-mentioned discharge recording is done within thefirst-floor patterning room 15. The air in the patterning room 15 isreplaced with compressed nitrogen gas to achieve a state in which themoisture density and the oxygen density within the chamber aremaintained below predetermined levels. In addition, inspection andadjustment of the nozzle heads 8 are done within the second-floormaintenance room 16. Note that the partitioning plate 14 need notnecessarily be disposed horizontally, provided it separates thepatterning room 15 and the maintenance room 16.

The patterning room 15 has dimensions such as 1500×1500×500 mm. A marblebase stand 17 is disposed on an upper surface of the base frame 2 in theroom 5. A support pillar 18 rises from each corner of the base stand 17.

As shown in FIGS. 1 and 2, a pair of box frames 37 that extend in thefront-to-rear direction (a sub scanning direction Y) are supported onthe support pillars 18 on the left and right sides above horizontalpartitioning plate 14 of the maintenance room 16. A support frame 38 isbridged between the box frames 37.

The description now turns to the medium holder moving device 5. At await position WP denoted by dot-dot-dash lines in FIG. 2, the mediumholder moving device 5 receives the glass substrate 4 that is supportedon and transported by the feed loader H from the rear of the droplet jetpatterning device 1, moves the substrate 4 to a predetermined automaticalignment start position, and then adjusts the alignment of the glasssubstrate 4 at an initial setting position. The medium holder movingdevice 5 also moves the glass substrate 4 in each of the X-axis andY-axis directions (a main scanning direction X and a sub scanningdirection Y) independently during discharge recording, and moves theglass substrate 4 to the wait position WP for transfer onto the feedloader H after the discharge recording.

As shown in FIG. 5, the medium holder moving device 5 is provided with amedium transfer mechanism 24, a substrate receptacle 21, a substratelift mechanism 23, and an angle adjustment device 35. The mediumtransfer mechanism 24 is a mechanism for moving the glass substrate 4 ineach of the main scanning direction X and the sub scanning direction Y,independently. The medium transfer mechanism 24 is provided with anX-axis slide mechanism 20, a Y-axis slide mechanism 19, an X-directiondrive portion 26, and a Y-direction drive portion 29.

As shown in FIG. 6, the Y-axis slide mechanism 19 is provided with aY-direction guide member 19 a mounted on the base stand 17 and an outputmember 19 b which can move in the sub scanning direction Y along theY-direction guide member 19 a. In addition, the X-axis slide mechanism20 is provided with an X-direction guide member 20 a mounted on the basestand 17 and an output member 20 b which can move in the main scanningdirection X along the X-direction guide member 20 a. The substratereceptacle 21 is provided on top of this output member 20 b. The glasssubstrate 4 is mounted on the substrate receptacle 21. The substratereceptacle 21 is made capable of rotating about a pin 22 shown in FIG.5.

As shown in FIG. 5, the Y-direction drive portion 29 is provided with aY-axis encoder 30 and a servomotor 31, to cause the output member 19 bto move along the Y-direction guide member 19 a. Similarly, theX-direction drive portion 26 is provided with an X-axis encoder 27 and aservomotor 28, to move the output member 20 b along the X-directionguide member 20 a. This configuration enables the glass substrate 4mounted on the substrate receptacle 21 to move in each of the mainscanning direction X and the sub scanning direction Y, independently.The actual discharge recording is done while the glass substrate 4 ismoved relative to the nozzle heads 8 in the main scanning direction Xand the sub scanning direction Y.

As shown in FIG. 38, the Y-axis slide mechanism 19 is further providedwith a Y-axis linear scale 198 that is capable of detecting an amount ofmovement of the output member 19 b precisely. The X-axis slide mechanism20 is further provided with an X-axis linear scale 189 that is capableof detecting an amount of movement of the output member 20 b precisely.

The substrate receptacle 21 is configured of a multiply perforatedmember of a synthetic resin or sintered metal. A negative pressure isapplied through the multiply perforated member to the glass substrate 4mounted on the substrate receptacle 21 in order to attract the substrate4 to the substrate receptacle 21. As shown in FIG. 5, the substratereceptacle 21 is formed to be wider than the glass substrate 4 in theleft and right directions. A pair of trays 21 a is integral with thereceptacle 21 on the left and right sides to accommodate flushingliquid, as will be described later. The substrate lift mechanism 23 isdesigned to lift the glass substrate 4 a predetermined small distancefrom the substrate receptacle 21 during transport in and out. Thesubstrate lift mechanism 23 is provided with four lift bars 23 a and anair cylinder (not shown in the figures) for raising and lowering thoselift bars 23 a.

The angle adjustment device 35 is provided with a cam piece 33 and anelectric cylinder 34. The cam piece 33 is frictionally engaged with theunder surface of the substrate receptacle 21. The electric cylinder 34is designed to move the cam piece 33 in the main scanning direction X bya small distance to rotate the substrate receptacle 21 about the pin 22.This configuration makes it possible to rotate the medium transfermechanism 24 mounted on the substrate receptacle 21 by just a desiredangle α, to correct the orientation of the medium transfer mechanism 24.

The description now turns to an automatic alignment adjustment mechanism36. The automatic alignment adjustment mechanism 36 is designed to movethe glass substrate 4 automatically at an initial setting position. Asshown in FIGS. 33, 35, and 38, large and small alignment marks AM1, AM2,AM3, and AM4 are printed in the left and right corners of thetrailing-edge side of the glass substrate 4. The automatic alignmentadjustment mechanism 36 uses these alignment marks AM1 to AM4 to obtainamounts of deviation from the initial setting position of the glasssubstrate 4, to ensure that the glass substrate 4 is placed at thatinitial setting position. The automatic alignment adjustment mechanism36 is configured of the previously-described X-axis and Y-axis slidemechanisms 20 and 19, the angle adjustment device 35, theinspection/adjustment stage 44 shown in FIG. 1, and a control device 13shown in FIG. 38. The X-axis and Y-axis slide mechanisms 20 and 19 andthe angle adjustment device 35 have already been described so thatfurther description thereof is omitted here, and the description nowrelates to the other components.

The inspection/adjustment stage 44 is provided in the maintenance room16 and is provided with low-magnification CCD cameras 32 a and 32 b,high-magnification cameras 32 c and 32 d, an X-direction movement drivemechanism 149, and a Y-direction movement drive mechanism 150, as shownin FIG. 3. The low-magnification CCD camera 32 a and thehigh-magnification CCD camera 32 c are attached to a common supportplate 145 on the left side of the aperture portion 14 a. These CCDcameras 32 a and 32 c are designed to image the alignment marks AM1 andAM3, respectively, that are positioned below a glass window (not shownin the figure) provided in the partitioning plate 14. The focus of theCCD cameras 32 a and 32 c can be adjusted individually by manualoperation. If the thickness of the glass substrate 4 changes, thevertical position of the CCD camera 32 a and the CCD camera 32 c can beadjusted by an air cylinder 146.

Similarly, the low-magnification CCD camera 32 b and thehigh-magnification CCD camera 32 d are attached to a common supportplate 147 on the right side of the aperture portion 14 a. These CCDcameras 32 b and 32 d are designed to image the alignment marks AM2 andAM4, respectively, that are positioned below a glass window (not shownin the figure) provided in the partitioning plate 14. The focus of theCCD cameras 32 b and 32 d can be adjusted individually by manualoperation. If the thickness of the glass substrate 4 changes, theheightwise position of the CCD camera 32 b and the CCD camera 32 d canbe adjusted by an air cylinder 148.

The X-direction movement drive mechanism 149 and the Y-directionmovement drive mechanism 150 are designed to move the support plate 147together with the CCD cameras 32 b and 32 d by small amounts in each ofthe X and Y directions, individually. If the positional error of theglass substrate 4 is large or the size of the glass substrate 4 changes,the positions of the alignment marks AM2 and AM4 on the right side maychange greatly in the X and Y directions. Even in such a case, thealignment marks AM2 and AM4 can be detected by moving the CCD cameras 32b and 32 d by an appropriate amount in the X and Y directions.

The method of adjusting the alignment of the glass substrate 4 on thesubstrate receptacle 21 to the initial setting position, using theautomatic alignment adjustment mechanism 36, will now be described indetail. First of all, the low-magnification CCD cameras 32 a and 32 bimage the larger alignment marks AM1 and AM2 to input the obtained imageinformation to the control device 13. The control device 13 processesand analyzes the input image information to analysis by a predeterminedcontrol program, to obtain displacement quantities ΔX and ΔY in the mainscanning direction X and the sub scanning direction Y from the initialsetting position of the glass substrate 4, as well as an angulardisplacement quantity Δα about the pin 22. The control device 13 thencontrols the X-axis and Y-axis slide mechanisms 20 and 19 and the angleadjustment device 35 in such a manner as to cancel the displacementquantities ΔX, ΔY, and Δα, to achieve rough positioning of the glasssubstrate 4 at the initial setting position.

The left and right high-magnification CCD cameras 32 c and 32 d thenimage the smaller alignment marks AM3 and AM4 to input the obtainedimage information to the control device 13. In a similar manner to thatdescribed above, the image information is analyzed by the control device13 to obtain displacement quantities ΔX, ΔY, and Δα from the initialsetting position of the glass substrate 4. The control device 13 thencontrols the X-axis and Y-axis slide mechanisms 20 and 19 and the angleadjustment device 35 to cancel the displacement quantities ΔX, ΔY, andΔα. This achieves precise positioning of the glass substrate 4 at theinitial setting position.

Since the plurality of CCD cameras 32 a to 32 d is provided in thismanner, it is possible to detect the position of the glass substrate 4held on the substrate receptacle 21 and then place the glass substrate 4at the origin position accurately, based on the detection results.

The description now turns to the Z-axis slide mechanism 6. The Z-axisslide mechanism 6 rises and lowers the nozzle head holder 7 so that thehead portion 43 of the nozzle head holder 7 is positioned selectivelyamong a discharge position (down position) DP, an inspection/adjustmentposition (up position) UP, and a home position HP that is slightlyhigher than the inspection/adjustment position UP, as shown in FIG. 6.Note that the discharge recording by the nozzle heads 8 is done at thedischarge position DP. Inspection and adjustment for the head portion43, which will be described later, is done at the inspection/adjustmentposition UP. The home position HP is a standby position for the nozzlehead holder 7.

As shown in FIG. 4, the Z-axis slide mechanism 6 is configured of aslide case 39, an output member 40 that can be guided into the slidecase 39, an electric cylinder 41 that raises and lowers the outputmember 40, and a Z-axis encoder 42 for the electric cylinder 41. Theslide case 39 is fixed to the previously mentioned support frame 38. Ahead assembly attachment stand 25 is fixed to the lower end of theoutput member 40. The nozzle head holder 7 is attached in a removablemanner to the head assembly attachment stand 25. More specifically, asshown in FIG. 9, the head assembly attachment stand 25 has a supportplate 47. The support plate 47 is fixed to the lower end of the outputmember 40 by a plurality of bolts 48. The nozzle head holder 7 issupported by this support plate 47, details of which will be describedlater.

The description now turns to the nozzle head holder 7. The nozzle headholder 7 is provided with a frame member 46 as shown in FIG. 14, afour-bar linkage 49, a pair of rotational pivots 50A and 50B, three headholders 51R, 51G, and 51B, two sets of guide mechanisms 52A and 52Bshown in FIG. 19, and movement mechanisms 53A and 53B. As shown in FIGS.27( a) and 27(b), the four-bar linkage 49 is configured to be able torotate about the centers of the rotational pivots 50A and 50B.

FIGS. 7 to 12 show the state in which the nozzle head holder 7 ismounted on the support plate 47. FIGS. 13 and 14 a show the state inwhich the nozzle head holder 7 has been removed from the support plate47. FIGS. 15 to 18 show the state in which the nozzle head holder 7 hasbeen removed from the support plate 47 and the frame member 46 isomitted.

The various members of the nozzle head holder 7 will now be described insequence. The description first concerns the frame member 46. As shownin FIG. 14, the frame member 46 has a main portion 46 a that extends inthe lateral direction, a left arm portion 46 b that extends forward fromthe left end of the main portion 46 a, and a right arm portion 46 c thatextends diagonally forward from the right end of the main portion 46 a.The rotational pivots 50A and 50B are supported on the left arm portion46 b and the arm portion 46 c, respectively.

A pair of attachment linkage mechanisms 67 having a similarconfiguration are provided on the left and right of a rearward portionof the frame member 46. The attachment linkage mechanisms 67 attach theframe member 46 removably to the support plate 47 of the head assemblyattachment stand 25. The configuration of the attachment linkagemechanisms 67 will now be described with reference to FIGS. 12 and 13.As shown in FIG. 12, a through hole 47 b and a through hole 46 d areformed in the support plate 47 and the frame member 46, respectively. Aball retainer 69 a, a bearing bush 69 b, and a retainer removalprevention ring 69 c are installed within the through hole 47 b so as tofit therein. A cylindrical bottomed metal fitting 68 is fixed by meansof bolts to a lower end portion corresponding to the through hole 47 bof the support plate 47. A ball retainer support spring 68 a isinstalled to urge the ball retainer 69 a upward. A ball retainer 71 a, abearing bush 71 b, and a retainer removal prevention ring 71 c areinstalled within the through hole 46 d so as to fit therein.

A pin assembly 70 is configured of a pin member 70 a, a cylindricalstopper member 70 b including a male thread, a nut plate 70 c, a knob 70d, and a retainer screw 70 e. The stopper member 70 b is attached to theouter periphery of the upper half of the pin member 70 a. The stoppermember 70 b is provided with a small-diameter portion 701, a male threadportion 702, and a flange-shaped removal prevention portion 703, in thatorder from the top. The nut plate 70 c is engaged with the male threadportion. The knob 70 d is then mounted on the outside of thesmall-diameter portion, and is fixed thereto by the retainer screw 70 e.The nut plate 70 c is finally fixed to the frame member 46.

When the nozzle head holder 7 is to be attached to the support plate 47,the through hole 46 d of the frame member 46 has been brought intoapproximate alignment with the through hole 47 b of the support plate47. And, the knob 70 d of the pin assembly 70 is then rotated to insertthe pin member 70 a into the through hole 47 b. The nozzle head holder 7is positioned accurately with respect to the support plate 47. At thistime, the ball retainer 69 a moves slightly downward against theresilient force of the ball retainer support spring 68 a. The nozzlehead holder 7 is then fixed to the support plate 47 by a pair of bolts45. When the nozzle head holder 7 is to be removed from the supportplate 47, on the other hand, the pair of bolts 45 is removed, and thenthe knob 70 is rotated to extract the pin member 70 a from the throughhole 47 b. Accordingly, the entire nozzle head holder 7 can be slidforward and detached from the support plate 47, as shown in FIG. 13. Atthis time, the pin assembly 70 is prevented from separating from theframe member 46 by the ball retainer 71 a moving upward and the removalprevention portion 703 coming into contact with the nut plate 70 c.

The description now turns to the head holders 51. As shown in FIG. 7,the head holders 51R, 51G, and 51B are formed to have an elongatedshape, and are provided in parallel at a predetermined spacing in themain scanning direction X. The two ends of each of the head holders 51are supported so as to be able to rotate about a vertical axis by a pairof first link members 56A and 56B. As shown in FIG. 23, correspondingnozzle heads 8 (8R, 8G, and 8B) are fixed by screws 99 through spacers98 to under surfaces of the head holders 51. These head holders 51, thecorresponding nozzle heads 8, and the spacers 98 together configure ahead body 500. In an initial setting state, the head holders 51 aredisposed parallel to the sub scanning direction Y.

The nozzle heads 8R, 8G, and 8B are formed of a solvent-resistantmaterial such as a ceramic material to discharge discharge-liquids forred (R), green (G), and blue (B), respectively. In this embodiment, asolution of an organic substance such as an EL light-emitting organicsubstance that is dissolved in a solvent is used as the dischargeliquid. As shown in FIG. 24, each of the nozzle heads 8 is provided witha number (such as 64) of small-diameter nozzles 55 arrayed in a singlerow in the longitudinal direction at a predetermined nozzle pitch (suchas at 75 dpi). The nozzles 55 of each nozzle head 8 are numbered 1, 2, .. . 64 in sequence from the furthermost end (a base end side). In thisembodiment, the No. 1 nozzle 55 of each nozzle head 8 is assigned as areference nozzle. The nozzle head 8R is assigned as a reference head.

The head holder 51R that acts as the reference head is provided so as tobe unable to move in the sub scanning direction Y. The head holders 51Band 51G are each provided so as to be able to move in the sub scanningdirection Y. The movement of the head holders 51B and 51G in the subscanning direction Y is done by the guide mechanisms 52A and 52B and themovement mechanisms 53A and 53B, shown in FIG. 19. These guidemechanisms 52A and 52B and movement mechanisms 53A and 53B will bedescribed later.

The description now turns to the four-bar linkage 49. The four-barlinkage 49 is a rotational mechanism for rotating the head holders 51,that is, the nozzle heads 8, about the reference nozzle of the referencenozzle 8, or a center in the vicinity thereof.

As shown in FIG. 14, the four-bar linkage 49 is provided with the pairof first link members 56A and 56B that extend in the main scanningdirection X at the front and the rear at a predetermined spacing and apair of second link members 57A and 57B that extend in the sub scanningdirection Y. A protruding portion 60 is formed on the rear-side firstlink member 56B to protrude a predetermined length beyond the right-sidesecond link member 57B. The first link members 56A and 56B and thesecond link members 57A and 57B are coupled together by four connectiveportions 61, so that the second link members 57A and 57B can rotateabout the connective portions 61, vertical axes.

The description now turns to these connective portions 61. Since allfour of the connective portions 61 have the same configuration, thedescription relates to the connective portion 61 that connects the firstlink member 56A and the second link member 57A. As shown in FIGS. 10 and17, a pin member 62 is provided to stand on the upper surface of thelink member 56A. A ball bearing bush 63 is provided vertically within athrough hole formed in an end portion of the second link member 57A. Thepin member 62 penetrates through the interior of the ball bearing bush63 and is prevented from falling out by a washer 64, a coil spring 65,and a hollow bolt 66.

The description now turns to the pair of rotational pivots 50A and 50B.As shown in FIG. 7, the rotational pivots 50A and 50B are rotationalpivots for rotating the four-bar linkage 49. Each of the rotationalpivots 50A and 50B is positioned at an intermediate part of the secondlink members 57A and 57B. In this embodiment, the rotational pivots 50Aand 50B are provided at positions that are at approximately one-third ofthe length from the rear end of the second link members 57A and 57B,respectively.

The reference nozzle (No. 1 nozzle) of the nozzle head 8R is positionedon a line BF that extends in the main scanning direction X through thecenters of the pair of rotational pivots 50A and 50B, as shown in FIG.28. This ensures that the reference nozzle of the reference nozzle head8R acts as the center of rotation of the reference nozzle 8R. Note thatthe reference nozzles of the nozzle heads 8G and 8B may be disposed onthe line BF, or that they may be displaced a very small distance in thesub scanning direction Y, if necessary.

The description first deals with the rotational pivot 50A. As shown inFIG. 7, the left-side rotational pivot 50A links the second link member57A to the left arm portion 46 b of the frame member 46 rotatably. Asshown in FIG. 10, a vertical pin member 75 is fixed to stand on theupper surface of the second link member 57A. A ball bearing bush 76 isinstalled vertically in a tip-end portion of the left arm portion 46 bof the frame member 46. The pin member 75 penetrates through the ballbearing bush 76 in a tightly fitting state. A washer 77, a coil spring78, and a hollow bolt 79 are installed on a protruding portion 75 a ofthe pin member 75 protruding from the ball bearing bush 76 to preventthe ball bearing bush 76 from falling out from the pin member 75. Whenthe four-bar linkage 49 is to be removed from the frame member 46, thepin member 75 can be removed from the ball bearing bush 76 by removingthe hollow bolt 79, the coil spring 78, and the washer 77.

The rotational pivot 50B has the similar configuration to that of therotational pivot 50A. The rotational pivot 50B links the second linkmember 57B to the arm portion 46 c of the frame member 46. As shown inFIGS. 9 and 16, another vertical pin member 75 is fixed to stand on thesecond link member 57B. Another ball bearing bush 76 is attached tostand upright on a leading end portion of the arm portion 46 c. Thewasher 77, coil spring 78, and hollow bolt 79 are installed on aprotruding portion of the pin member 75 that penetrates the ball bearingbush 76 in a tightly fitting state.

The description now concerns a rotational drive mechanism 80 shown inFIG. 9. The rotational drive mechanism 80 is designed to exert arotational moment on the rotational pivot 50B to rotate the four-barlinkage 49 about the rotational pivots 50A and 50B. The rotational drivemechanism 80 has a motor 82 with speed reducer, a lever member 83, arotational force input shaft 84, and a motor support plate 85. The motor82 with speed reducer rotates about the same center as the rotationalpivot 50B (see FIG. 7). The motor support plate 85 is fixed to theoutput member 40 of the Z-axis slide mechanism 6. The motor 82 withspeed reducer is attached to this motor support plate 85 in anupward-facing attitude.

As shown in FIG. 16, the rotational force input shaft 84 has a pinmember 87 that is provided vertically in front of the rotational pivot50B on the second link member 57B, a spacer 88, a ball bearing bush 89,and a hollow bolt 90. As shown in FIG. 20, the lever member 83 has amain lever body 83 a and a resilient plate 83 b that support the ballbearing bush 89 from the left and right sides. As shown in FIGS. 8 and11, a rear position of the main lever body 83 a is fixed to an outputshaft 82a of the motor 82 with speed reducer by a bolt 91. The resilientplate 83 b is fixed to the rear portion of the main lever body 83 a by abolt 92.

As shown in FIG. 20, when the output shaft 82 a of the motor 82 withspeed reducer rotates, the lever member 83 rotates integrally with therotational force input shaft 84 about the output shaft 82 a. In thiscase, since the rotational force input shaft 84 is fixed to the secondlink member 57 B as described previously, the second link member 57Brotates to an angle that is the same rotation angle of the output shaft82 a about the output shaft 82 a. As a result, the second link members57A and 57B and the three head holders 51 rotate by just the same angle.In this embodiment, the second link members 57A and 57B can be rotatedat any desired angle with respect to the sub scanning direction Y,within the range of 0 to 60 degrees.

The description now turns to an inclination angle detection encoder 81shown in FIG. 7. The inclination angle detection encoder 81 is ahigh-resolution rotary encoder to detect the rotational angle θ withrespect to the sub scanning direction Y of the four-bar linkage 49rotated by the rotational drive mechanism 80. As shown in FIG. 7, aninput shaft 81 a of the encoder 81 is fixed in an upward-facing attitudeon an extension portion 47 a of the support plate 47. The axial centerof the input shaft 81 a is positioned on the line BF that links theaxial centers of the rotational pivots 50A and 50B. An arm 95 is fixedto the input shaft 81 a. A roller 95 a is pivoted about a leading endportion of the arm 95. The arm 95 is pressed resiliently in thecounterclockwise direction in FIG. 7 by a resilient member 93 so thatthe roller 95 a is resiliently in contact with a right end surface ofthe protruding portion 60 of the first link member 56B, as shown in FIG.19. Note that a stopper groove 96 of the support plate 47, denoted by adot line in FIG. 7, is a stopper groove for holding the arm 95 at asuitable position when the nozzle head holder 7 is removed. The stoppergroove 96 is configured to prevent the nozzle head holder 7 frominterfering with the arm 95 when the nozzle head holder 7 is attached tothe support plate 47.

When the four-bar linkage 49 rotates in the clockwise direction of FIG.27( b) about the rotational pivots 50A and 50B, the first link member56B moves to the right. Therefore, the arm 95 that extends in the subscanning direction Y shown in FIG. 27( a) in the initial setting staterotates in parallel to the second link members 57A and 57B, as shown inFIG. 27( b). This configuration makes it possible to precisely detectthe rotational angle θ of the four-bar linkage 49 by using the encoder81.

Thus, if the motor 82 with speed reducer is controlled by the controldevice 13 while the detected rotational angle θ is fed back thereto, anydesired rotational angle θ can be obtained. The desired rotational angleθ is determined on the basis of a predetermined resolution R for patternformation, as will be described later.

The description now turns to the guide mechanisms 52A and 52B that guidethe head holders 51B and 51G in the sub scanning direction Y. It shouldbe noted that since the guide mechanisms 52A and 52B have the sameconfiguration, the description deals only with the guide mechanism 52A,with that of the guide mechanism 52B being omitted. The guide mechanism52A is designed to support the head holder 51B (nozzle head 8B) to moveit parallel to the sub scanning direction Y with respect to the firstlink members 56A and 56B. The guide mechanism 52A has a front-end guidemechanism 100 and a rear-end guide mechanism 101, as shown in FIG. 21.

The description first deals with the front-end guide mechanism 100. Asshown in FIG. 23, a roller member 102A is attached to the lower surfaceof the head holder 51 so as to rotate about a vertical axis, a supportshaft 107A. As shown in FIGS. 16 and 21, a concavity 103A is formed inan upper surface of the link member 56A, with the roller member 102A anda pressure member 105A being accommodated therein. As shown in FIG. 21,a right-side surface of the concavity 103A forms a guide surface 104A.The pressure member 105A is supported in the link member 56A so that thepressure member 105A is able to rotate about a rotational shaft 105 a.One end of the pressure member 105A is urged by a pressure coil spring106A to rotate clockwise. The other end of the pressure member 105A isin contact with the roller member 102A, pressing the roller member 102Aagainst the guide surface 104A.

The description now deals with the rear-end guide mechanism 101. Therear-end guide mechanism 101 has a similar configuration to thefront-end guide mechanism 100. The rear-end guide mechanism 101 isconfigured of a roller member 102B, a concavity 103B formed in the firstlink member 56B, a guide surface 104B of the concavity 103B, a pressuremember 105B, and a pressure coil spring 106B, as shown in FIG. 21. Thepressure member 105B that is supported rotatably is urged by thepressure coil spring 106B. This structure causes the roller member 102Bto be pressed rearwardly and rightwardly against the guide surface 104B,thereby being in contact with the spindle 108.

A pair of roller members 102A and 102B provided at each end of the headholder 51R is engaged in guide holes of the first link members 56A and56B, respectively, which prohibits the head holder 51R from moving inthe sub scanning direction Y.

The description now turns to the movement mechanisms 53A and 53B. Themovement mechanisms 53A and 53B are movement mechanisms for moving thehead holders 51B and 51G by small distances in the sub scanningdirection Y. Since the movement mechanisms 53A and 53B have the sameconfiguration, the description here relates to the movement mechanism53B alone. As shown in FIG. 15, a bracket 112 is fixed to a rear surfaceof the first link member 56B. The movement mechanism 53B is attached tothe bracket 112. As shown in FIG. 21, the movement mechanism 53B isprovided with a spindle 108 provided at a leading end portion thereof,an input portion 114 provided at a rear end portion thereof, and arotation control portion 115. The spindle 108 protrudes partially intothe concavity 103B. The leading end of the spindle 108 is in contactwith a roller member 102 from the rear, as is previously described. Therotational force from a position adjustment drive mechanism 113, whichwill be described later, is received to the input portion 114 so thatthe input portion 114 rotates.

When the input portion 114 rotates in a predetermined direction, thespindle 108 moves forward. In this case, the roller member 102B movesforward against the pressure coil spring 106B. Simultaneously, theroller member 102A also moves forward in the concavity 103A.Accordingly, the entire head holder 51B moves forward. When the inputportion 114 rotates in the opposite direction, on the other hand, thespindle 108 moves rearward so that the roller member 102B is movedrearward to follow the leading end of the spindle 108 by the pressurecoil springs 106A and 106B. Thus, the whole of head holder 51B movesrearward. As described above, the spindle 108 can be moved forward andback by the small distance proportional to the rotational angle (φ) ofthe input portion 114 in a predetermined direction corresponding to therotational direction, so that the position of the head holder 51B can beadjusted in the sub scanning direction Y.

In addition, since the roller members 102A and 102B move forward andrearward along the corresponding guide surfaces 104A and 104B, the headholder 51B can move parallel to the sub scanning direction Y regardlessof the rotation of the four-bar linkage 49, as shown in FIGS. 27( a) and27(b). Note that the rotation control portion 115 is controlled byfriction on the input portion 114, to ensure that the spindle 108 doesnot rotate freely during printing.

The description now turns to the configuration including the head holder51, with reference to FIGS. 7, 16, and 18. As shown in FIG. 7, pressingplates 58A and 58B are disposed on the upper surfaces of the three headholders 51, and attached in a removable manner to the first link members56A and 56B by a plurality of bolts 97. As shown in FIG. 18, spacers 59are disposed between the pressing plates 58A and 58B and the first linkmembers 56A and 56B and between neighboring head holders 51. Each of thespacers 59 is fixed by a plurality of bolts 97. Since the spacers 59 areformed to be approximately 5 μm thicker than the head holders 51, a gapof approximately 5 μm is formed between the head holders 51 and thepressing plates 58A and 58B, as shown in FIG. 23. This gap allows thetwo end portions of each head holder 51 to rotate with respect to thepair of first link members 56A and 56B, thereby moving each head holder51 in the sub scanning direction Y as described above.

In this case, as shown in FIG. 23, the support shafts 107A and 107B areformed to protrude upward from the upper surface of the head holders 51.Concavities 109A and 109B are formed in the lower surfaces of thepressing plates 58A and 58B. Protruding portions 107 a of the supportshafts 107A and 107B are accommodated in the concavities 109A and 109B.A pressure coil spring 110 and a spring receptacle cap 111 are installedin each protruding portion 107 a (see FIG. 22). The head holders 51 isurged downward by the force of the pressure coil spring 110.Accordingly, the lower surfaces of the head holders 51 are in contactwith upper surfaces of the first link members 56A and 56B. On the otherhand, the roller members 102A and 102B are in contact with the basesurfaces of the concavities 103A and 103B, as shown in FIG. 16. Thus,the heightwise position of the head holders 51 is set with respect tothe first link members 56A and 56B precisely. And the nozzles 55 arepositioned in the vertical direction.

The description now turns to the position adjustment drive mechanism 113that drives the movement mechanisms 53A and 53B. The position adjustmentdrive mechanism 113 is a mechanism for causing the head holders 51B and51G to move in the sub scanning direction Y, as described previously.And, the position adjustment drive mechanism 113 is disposed on therearward side of the aperture portion 14 a within the second-floormaintenance room 16, as shown in FIGS. 2 and 3.

As shown in FIG. 3, the position adjustment drive mechanism 113 isprovided with a Y-direction drive mechanism 116 including an aircylinder, an X-direction drive mechanism 117 including an air cylinder,and a servomotor 118. The Y-direction drive mechanism 116 is designed todrive the X-direction drive mechanism 117 to move in the sub scanningdirection Y. The X-direction drive mechanism 117 is designed to drivethe servomotor 118 to move in the X direction. The servomotor 118 has anoutput portion 119 that is disposed facing forward. The output portion119 is designed to transfer the motor drive force to the input portion114 of the movement mechanisms 53A and 53B. The parallel movement in thesub scanning direction Y of the head holders 51B and 51G by the positionadjustment drive mechanism 113 is described below.

First of all, after the Z-axis slide mechanism 6 has been used to setthe nozzle head holder 7 in the inspection/adjustment position UP, theservomotor 118 is made to move laterally to adjust the position of theoutput portion 119 to be concentric with the input portion 114 of themovement mechanisms 53A or 53B. The Y-direction drive mechanism 116 isthen used to move the servomotor 118 forward to engage the outputportion 119 with the input portion 114. The input portion 114 is rotatedby the transfer of motor drive force to the input portion 114 throughthe output portion 119, to cause the head holders 51B and 51G to move inthe sub scanning direction Y in the previously described manner.

Examples of the dispositions of R, G, and B dots that form one group ofpixels in the EL light-emitting layer are shown in FIGS. 29( a) to29(c). In one example shown in FIG. 29( a), either one of the G dot orthe B dot is shifted in the sub scanning direction Y with respect to theR dot. In other examples shown in FIGS. 29( b) and 29(c), both of the Gdot and the B dot are shifted in the sub scanning direction Y withrespect to the R dot. These dot dispositions can be obtained bypositional adjustment of the head holders 51B and 51G independently inthe sub scanning direction Y, as described above.

The description now turns to the second-floor maintenance room 16 andthe devices in the interior thereof. In the maintenance room 16, thedischarge state of the plurality of nozzles 55 of the nozzle heads 8R,8G, and 8B are inspected by a discharge inspection mechanism 121.Maintenance of the nozzle head holder 7 itself is done.

The maintenance room 16 has dimensions such as 1500×1500×700 mm. In themaintenance room 16, most of the Z-axis slide mechanism 6, the positionadjustment drive mechanism 113, part of the automatic alignmentadjustment mechanism 36, and the inspection/adjustment device 9 aredisposed. The inspection/adjustment device 9 is a device for inspectingand maintaining the nozzle heads 8 of the head holders 51. Theinspection/adjustment device 9 is provided with a head maintenancemechanism 123 and the discharge inspection mechanism 121, as shown inFIG. 2.

The head maintenance mechanism 123 is provided slightly forward of theaperture portion 14 a in the maintenance room 16.

The head maintenance mechanism 123 has an electric cylinder 124, ablotting paper feed mechanism 125, a paper feed drive mechanism 126, apressurized purge tray 127, a rubber pad 128 for capping, and a movabletable 129, as shown in FIG. 34

The blotting paper feed mechanism 125, the tray 127, and the rubber pad128 are supported integrally on the movable table 129. The electriccylinder 124 causes the movable table 129 to be driven to move in thesub scanning direction Y, thereby disposing the blotting paper feedmechanism 125, the tray 127, or the rubber pad 128 selectively under thenozzle heads 8 at the inspection/adjustment position UP.

The blotting paper feed mechanism 125 is designed to perform a wipingprocessing provided in printing, for blotting up droplets remaining onthe nozzle surfaces of the nozzle heads 8 with blotting paper 136 toreturn the meniscuses of the nozzles 55 into a normal condition after apressurized purge, which will be described later. The blotting paperfeed mechanism 125 is provided with a drive roller 130, a back-tensionmechanism 132, follower rollers 133 and 134, and a support plate 135.The drive roller 130 is a drive roller of a one-way clutch type that isdriven by the paper feed drive mechanism 126. The back-tension mechanism132 is provided with a follower roller 131 a and a belt 131 b. The belt131 b is mounted between the drive roller 130 and the follower roller131 a. The blotting paper 136 is provided on the follower roller 131 a.The blotting paper 136 is wound around the drive roller 130 via thefollower rollers 133 and 134 by rotating the drive roller 130. At thistime, a constant tension is applied to the blotting paper 136 in thedirection opposite to the winding direction, by the back-tensionmechanism 132.

The paper feed drive mechanism 126 is provided with a servomotor 137, anX-direction slide mechanism 138, and an air cylinder 139 for slidedriving. A rubber piece (not shown in the figure) having a highcoefficient of friction is fixed around an output shaft 137 a of theservomotor 137. The X-direction slide mechanism 138 supports theservomotor 137 in a freely sliding manner in the main scanning directionX. The air cylinder 139 for slide driving is designed to drive theoutput shaft 137 a of the servomotor 137 to move between a predetermineddrive force transfer position and a non-transfer position.

The electric cylinder 124 drives the movable table 129 to apredetermined blotting paper winding position. Simultaneously, the aircylinder 139 for slide driving switches the output shaft 137 a of theservomotor 137 to the drive force transfer position. The rotationaldrive force of the servomotor 137 is transferred to the input shaft ofthe drive roller 130 to feed the blotting paper 136 in the directionindicated by the arrow in FIG. 34.

The pressurized purge tray 127 is provided with three concavities 127B,127G, and 127R. The nozzle heads 8 are moved with respect to thepressurized purge tray 127 to face these concavities 127B, 127G, and127R from above. The nozzles 55 are cleaned by supplying a flushingliquid 11 to each of the nozzle heads 8B, 8G, and 8R and discharging theliquid from the nozzles to the concavities 127B, 127G, and 127R. Duringdischarge inspection, discharge from the nozzles 55 is done for eachnozzle head 8. This configuration makes it possible to recover thedroplets that are discharged from the nozzle heads 8 into theconcavities 127B, 127G, and 127R without spattering of the surroundings,during the discharge inspection by the discharge inspection mechanism121.

The rubber pad 128 for capping has three rubber pads 128B, 128G, and128R. The nozzle heads 8B, 8G, and 8R are capped by the correspondingrubber pads 128B, 128G, and 128R, to prevent the nozzles 55 from dryingout while the droplet jet patterning device 1 is suspended.

The description now turns to the discharge inspection mechanism 121. Asshown in FIG. 2, the discharge inspection mechanism 121 is disposedwithin the second-floor maintenance room 16 at symmetrical positions onthe left and right sides of the aperture portion 14 a in the vicinity ofthe head maintenance mechanism 123.

As shown in FIGS. 3 and 30, the discharge inspection mechanism 121 hasimaging position switching mechanisms 141 a and 141 b, a CCD camera 142for imaging the discharge state of the droplets, and a strobe floodlight143 for lighting the CCD camera 142.

The CCD camera 142 is disposed on the left side and the strobefloodlight 143 is disposed on the right side. The imaging positionswitching mechanism 141 a is provided with a Y-direction drive mechanism140 a for moving the CCD camera 142 in the sub scanning direction Y andupper and lower two-stage air cylinders 144 for moving the CCD camera142 in two stages in the main scanning direction X. The imaging positionswitching mechanism 141 b is provided with a Y-direction drive mechanism140 b for moving the strobe floodlight 143 in the sub scanning directionY and upper and lower two-stage air cylinders 144 similar to thecylinders 144 described above.

The description now turns to details of the discharge inspection method.The inspection of the discharge status of the three nozzle heads 8B, 8G,and 8R is done for each of the nozzle heads 8. Since 64 nozzles 55 areformed in each of the nozzle heads 8, the discharge inspection is donefor each group of nozzles, such as one group having 16 nozzles, onegroup having as nozzles No. 1 to No. 16, another group having nozzlesNo. 17 to No. 32. In other words, the CCD camera 142 and the strobefloodlight 143 are set at initial positions in the sub scanningdirection Y. And the discharge status of the first group of nozzles No.1 to No. 16 is then examined. Subsequently, the CCD camera 142 and thestrobe floodlight 143 are moved forward by the Y-direction drivemechanisms 140 a and 140 b by the distance of 16 nozzles, to inspect thedischarge status of the second group of nozzles No. 17 to No. 32. Thedischarge of the third and fourth groups of nozzles is then tested in asimilar manner.

To ensure that the discharge inspection of the nozzles 55 of the nozzleheads 8R, 8G, and 8B is done under the same conditions during this time,the distance between the CCD camera 142 and the strobe floodlight 143 isalways kept constant and also the droplets are discharged and imaged atan intermediate position between the CCD camera 142 and the strobefloodlight 143. For that reason, the positions of the CCD camera 142 andthe strobe floodlight 143 can be switched in three stages in the mainscanning direction X dependently on the one of the three nozzle heads8R, 8G, and 8B that is being inspected. This position switching isdescribed below.

That is to say, when the nozzle head 8R is inspected, the two-stage aircylinders 144 of the left-side imaging position switching mechanism 141a are extended to the maximum limit, and the two-stage air cylinders 144of the right-side imaging position switching mechanism 141 b are at themost compressed. When the nozzle head 8G is inspected, one of thetwo-stage air cylinders 144 of the left-side imaging position switchingmechanism 141 a is contracted, and one of the two-stage air cylinders144 of the right-side imaging position switching mechanism 141 b isextended. In addition, when the nozzle head 8B is inspected, thetwo-stage air cylinders 144 of the left-side imaging position switchingmechanism 141 a are most contracted, and the two-stage air cylinders 144of the right-hand imaging position switching mechanism 141 b areextended to the maximum limit.

Since the Y-direction drive mechanisms 140 a and 140 b and the imagingposition switching mechanisms 141 a and 141 b are provided, and the CCDcamera 142 and the strobe floodlight 143 can move in each of the mainscanning direction X and the sub scanning direction Y in this manner,discharge from a plurality of the nozzles 55 of the plurality of nozzleheads 8 can be implemented sequentially and reliably. Since the imagingcan be done in a state in which the relative positions of the CCD camera142 and the strobe floodlight 143 with respect to the nozzle heads 8 tobe inspected are always kept constant, the reliability of the dischargedetection can be increased.

The description now turns to the discharge inspection technique thatdetermines the quality of the discharge of the nozzles 55. As shown inFIG. 31, 16 observation windows 151 corresponding to 16 nozzles 55 areset at a constant spacing in the sub scanning direction Y within apicture area PA (of approximately 6.5 mm×5 mm) of the CCD camera 142.Each of the observation windows 151 is set to a position approximately1.5 mm downward from the lower end of the corresponding nozzle 55. Theobservation window 151 has a rectangular shape of 60 pixels long and 10pixels wide, as shown in FIG. 32.

Droplets are discharged at a speed of approximately 7 m/s, by way ofexample, from each of the 16 nozzles 55 of the nozzle group beinginspected, and the droplets are imaged through the observation windows151. Assume that the shutter speed of the CCD camera 142 isapproximately 1/10,000 second. The strobe emission time is approximately1 μsec. The captured image signals are supplied to the control device 13and are then processed by a predetermined image processing program. Inthis image processing, the status is determined to be normal if most ofthe droplets from the nozzle heads 8 are within the observation windows151, and abnormal if not, by way of example. In the example shown inFIG. 31, the droplets from nozzles No. 1 to No. 7, No. 9, No. 10, andNo. 12 to No. 16 are within the observation windows 151. The dropletsfrom nozzles No. 8 and No. 11, on the other hand, are outside theobservation windows 151. Factors such as abnormal discharge speed,failed discharge, or accumulation of foreign bodies (mainly temporaryadhesion of EL polymers) are considered as causes of dischargeabnormality.

In this manner, the droplets discharged from a plurality of the nozzles55 are imaged by the CCD camera 142, and the quality of discharged canbe determined in a simple manner by processing and determining the imagedata. Since this determination can be done automatically by the controldevice 13 acting as an image processing means for inspection, thedischarge inspection can be performed efficiently.

Since this discharge inspection can be done with the nozzle head holder7 being raising it to the inspection/adjustment position UP, remaininginstalled on the output member 40 of the Z-axis slide mechanism 6, thedischarge inspection can be implemented during suspended period withinthe process of discharge recording on the glass substrate 4. For thatreason, the operating efficiency of the droplet jet patterning device 1can be increased even further.

The description now turns to control over the discharge recording of theR, G, and B dot patterns on the glass substrate 4 at various recordingresolutions. Note that this control is done by a host control unit 173of the control device 13 (see FIG. 38).

Since the nozzle pitch of the nozzle heads 8 is 75 dpi, as mentionedpreviously, the nozzle pitch (distance between nozzles) P is given by:P=(25.4/75) mm. If the three head holders 51 are rotated by the angle θtogether with the second link members 57A and 57B, the nozzle pitch Pθin the sub scanning direction Y is given by: Pθ=P×cos θ. If the angle θis varied within the range of 0 to 60 degrees, it is possible todecrease the nozzle pitch continuously within the range of P×(1.0) toP×(0.5). Specific examples of resolution setting are described below.

-   a) For Resolutions from 75 to 150 dpi (see FIGS. 35 and 36):

The rotation angle θ of the nozzle heads 8 to an angle that gives thedesired dpi in the sub scanning direction Y, within the range of 0 to 60degrees is set. And the glass substrate 4 is moved backward (in thedirection opposite to the sub scanning direction Y) by a distance ofjust {64×P×cos θ} for each pass of discharge recording in the mainscanning direction X. For 75 dpi, θ is 0 degrees, and for 150 dpi, 0 is60 degrees, by way of example.

-   b) For Resolutions from 150 to 300 dpi (see FIG. 37):

Discharge recording at a resolution of 150 dpi can be achieved byinterlaced discharge recording by which the head holder 51 is displacedby just half the pitch after discharge recording at a resolution of 75dpi, as shown by the broken lines in the figure. The rotation angle θ ofthe nozzle heads 8 is set to an angle that achieves a dpi that is halfthe desired dpi in the sub scanning direction Y, within the range of 0to 60 degrees, in the same way as described above. After one pass ofdischarge recording in the main scanning direction X, the glasssubstrate 4 is moved minutely by 0.5×P×cos θ rearward and another onepass of discharge recording is done. And then the glass substrate 4 ismoved rearward by just 63.5×P×cos θ. For 150 dpi, for example, θ=0°, andfor 300 dpi, θ=60°.

-   c) For Resolutions from 37.5 to 75 dpi:

The rotation angle θ of the nozzle heads 8 is set to an angle that givesa dpi that is twice the desired dpi in the sub scanning direction Y,within the range of 0 to 60 degrees. And the odd-numbered nozzles No. 1,No. 3, No. 5, . . . are used for one pass of discharge recording in themain scanning direction X, and then the substrate is stepped rearward by64×P×cos θ. For 37.5 dpi, for example, θ=0°, and for 75 dpi, θ=60°.

In this manner, the rotation angle θ of the nozzle heads 8 is controlledwithin the range of 0 to 60 degrees by the rotational drive mechanism80, based on an arbitrary discharge resolution. Note that more detailedapplication of interlacing makes it possible to perform dischargerecording at 225 to 450 dpi, or 300 to 600 dpi, or any other resolution.

The description now turns to correction control for correctingdifferences in nozzle pitch of the nozzle heads 8 by the rotation angleθ. This control is implemented by the host control unit 173 of thecontrol device 13. Correction control is done on the basis of theranking of the nozzle heads 8, so the description first concerns theranks of the nozzle heads 8.

As shown in FIG. 24, if the actual dimension between the nozzles at thefront and rear ends of the nozzle heads 8 is L1 and the theoreticaldimension between nozzles is L0, the error therebetween ΔL is given by:ΔL=(L1−L0). Thus, if the number of nozzles is n, the nozzle pitch errorΔP is given by: ΔP=ΔL(n−1). In general, it is rare to have a pluralityof nozzle heads 8 with nozzle pitch errors ΔP that are all the same. Inthe manufacturing process of the droplet jet patterning device 1, theactual inter-nozzle dimension L1 is measured for a large number ofnozzle heads 8 that have been prepared previously, and five-stagerankings such as rank 1, 2, . . . 5 are assigned to the nozzle heads 8on that basis of the measured dimension, as shown in FIG. 25. When thethree nozzle heads 8R, 8G, and 8B installed in one nozzle head holder 7are configured of nozzle heads 8 of the same rank, the nozzle pitcherrors ΔP in the plurality of nozzle heads 8 are approximated. Inaddition, assigning such rankings to the nozzle heads 8 also facilitatesmanagement of a large number of nozzle heads 8.

The description now turns to specific details of the correction controlfor correcting the rotational angle θ in accordance with the ranking ofthe nozzle heads 8. If the nozzle pitch between adjacent nozzles (settheoretical value) is P0 and the number of nozzles is n, L0 is expressedby: L0=P0×(n−1). The nozzle pitch (actual measured value) P1 can beexpressed as follows, using the actual inter-nozzle dimension L1, thetheoretical inter-nozzle dimension L0, and the number n of nozzles:

$\begin{matrix}{{P\; 1} = {{L\;{1/\left( {n - 1} \right)}} = {\left( {{\Delta\; L} + {L\; 0}} \right)/\left( {n - 1} \right)}}} \\{= {\left\{ {{\Delta\; L} + {P\; 0 \times \left( {n - 1} \right)}} \right\}/\left( {n - 1} \right)}} \\{= {{\Delta\;{L/\left( {n - 1} \right)}} + {P\; 0}}}\end{matrix}$

If the resolution in the sub scanning direction Y of the recordingpattern is R and the rotational angle θ is used, the apparent nozzlepitch PY as seen in the sub scanning direction Y is given by: PY=P1×cosθ. Thus following relationship holds:

$\begin{matrix}{{PY} = {25.4/R}} \\{= {P\; 1 \times \cos\;\theta}} \\{= {\left\lbrack {{\Delta\;{L/\left( {n - 1} \right)}} + {P\; 0}} \right\rbrack \times \cos\;\theta}}\end{matrix}$ θ = cos⁻¹(25.4/R)/[Δ L/(n − 1) + P 0]

In other words, it is theoretically possible to calculate the rotationalangle θ based on the resolution R. However, a desired resolution Rcannot be obtained from the above equations because of the nozzle pitcherror ΔP. In this case, an addition rotation by the angle Δθcorresponding to the nozzle pitch error ΔP makes it possible tosubstantially remove errors in the discharge recording caused by thenozzle pitch error ΔP, and increase the precision with which the patternis formed. In other words, the nozzle pitch error ΔP can be corrected toachieve the desired resolution R by increasing the rotational angle θ ifthe nozzle pitch error ΔP has a positive value, or decreasing therotational angle θ if the nozzle pitch error ΔP has a negative value.

Thus, if the resolution R and the nozzle pitch error ΔP are obtained, itis possible to calculate the actual rotational angle θ′(θ+Δθ). The angleΔθ of this embodiment is obtained by using the central error (+10, +5,0, −5, or −10 μm) for each rank, as shown in FIG. 25. Obtaining thecentral error from the angle Δθ generally enables accurate correction.Since nozzle heads 8 having the same ranking are used in thisembodiment, it is possible to increase the correction precision of therotational angle θ. Note that the central error is the value between theupper limit and the lower limit of the inter-nozzle dimension error ΔLfor each rank. If the nozzle pitch errors ΔP of the plurality of nozzleheads 8 are all the same, the nozzle pitch errors ΔP itself can be useddirectly instead of the central value, in the method of calculating theangle Δθ.

Note that when the rotational angle θ is calculated, a correctionprocessing program that uses the corresponding central error from thecentral errors for ranks 1 to 5 for correcting the rotational angle θcan be stored in the control device 13 beforehand. It should be notedthat the nozzle pitch error between adjacent nozzles (in other words,the value of the inter-nozzle dimension error ΔL divided by the numberof spaces between the nozzles) may be used instead of the inter-nozzledimension error ΔL.

The above equations enable the nozzle pitch error ΔP to be cancelled byrotating the rotational angle θ, within a range that satisfies thecondition 0≦θ≦60°, in other words, 0.5≦cos θ≦1. It should be noted,however, that the original θ=0° ought to be valid when P1×cosθ=25.4/R=P0. However, if the actual inter-nozzle dimension L1 isshorter, P1≦P0 and cos θ≧1, so that P1×cos θ=25.4/R=P0 cannot besatisfied. In addition, the original θ=60° ought to be valid when25.4/R=P0/2. However, if the actual inter-nozzle dimension L1 is longer,P0≦P1 and cos θ≦0.5, so that 25.4/R=P0/2=P1×cos θ cannot be satisfied.In such a case, the discharge recording can be done by returning therotational angle θ to 0° and inserting an interlace stage (pass).

The description now turns to the liquid supply mechanism 12. As shown inFIG. 2, the liquid supply mechanism 12 is provided on a side surface ofthe casing 3. As shown in FIG. 26, the liquid supply mechanism 12 isprovided with three liquid containers 152R, 152G, and 152B, a wasteliquid recovery container 153, and a washing solvent container 154. Allof these are accommodated in a glove box 172 and can be replaced througha hatch (not shown in the figure).

Discharge liquids 10 in R, G, or B for forming EL light-emitting layersin three colors are accommodated in the liquid containers 152R, 152G,and 152B, respectively. The discharge liquids 10 within the liquidcontainers 152R, 152G, and 152B are supplied to each of the nozzle heads8R, 8G, and 8B through a valve unit 155 and is then discharged asdroplets from the plurality of nozzles 55. Note that the liquidcontainers 152R, 152G, and 152B are raised and lowered in linkage withthe raising and lowering of the Z-axis slide mechanism 6, as will bedescribed later.

A washing solvent (flushing liquid) 11 that is used for washing thenozzle heads 8 is accommodated in the washing solvent container 154.When the nozzle heads 8 are washed, the flushing liquid 11 is suppliedfrom the washing solvent container 154 through the valve unit 155 to thenozzle heads 8R, 8G, and 8B, to perform a pressurized purge from theplurality of nozzles 55. This pressurized purge is performed by thepreviously described head maintenance mechanism 123. In other words,tubes (not shown in the figures) are connected to the concavities 127B,127G, and 127R of the pressurized purge tray 127 shown in FIG. 34, andwaste liquid is sucked through the tubes by negative pressure. Thethus-recovered waste liquid is recovered into the waste liquid recoverycontainer 153 through the valve unit 155 shown in FIG. 26. Note thatthis negative pressure is generated by using a vacuum pump or ejector(not shown in the figures) and the exhaust thereof is released into anorganic exhaust duct of the equipment.

A tube 156 is connected to the waste liquid recovery container 153, andthe waste liquid recovery container 153 is connected to a mistseparation tank outside the figure through the tube 156. The liquidcontainers 152R, 152G, and 152B and the washing solvent container 154are connected through tubes 157, 158, 159, and 160 and the valve unit155 to a compressed nitrogen gas line, respectively.

The description now turns to the mechanism by which the liquidcontainers 152R, 152G, and 152B are raised and lowered in linkage withthe raising and lowering of the Z-axis slide mechanism 6. As shown inFIG. 26, the liquid supply mechanism 12 is further provided with asupport frame 161, a movable frame (support stand) 162, a liquidcontainer elevator mechanism 163, and three liquid surface positionmaintenance mechanisms 166. The movable frame 162 is attached to thesupport frame 161 in a vertically movable manner. The liquid containerelevator mechanism 163 has an electric cylinder 164 with a metalbellows. A tip end of the rod 164 a of the electric cylinder 164 isconnected to the movable frame 162. The raising and lowering of theelectric cylinder 164 is linked to the raising and lowering of theZ-axis slide mechanism 6, with the movable frame 162 moving up and downalong the support frame 161. This keeps the height relationship betweenthe movable frame 162 and the nozzle heads 8R, 8G, and 8B constant.

The liquid surface position maintenance mechanisms 166 follow theconsumption of liquid in the liquid containers 152R, 152G, and 152B andare designed to ensure that the height of the liquid surface within eachof the liquid containers 152R, 152G, and 152B is kept at a referenceheight that is a predetermined distance (such as 50 mm) lower than theposition of the nozzles 55. As shown in FIG. 26, each of the liquidsurface position maintenance mechanisms 166 is provided with acylindrical casing 168 that is disposed vertically, a shaft-shapedmember 169, a compression coil spring 170 that acts as a resilientmember, a sleeve 171, and a holder 165R, 165G, and 165B for holding thecorresponding liquid container 152R, 152G, and 152B.

A flange 168 a is formed at an upper end portion of the casing 168, sothat the flange 168 a is linked removably to the movable frame 162. Theshaft-shaped member 169 is attached integrally to the interior of thecasing 168 and an upper end portion thereof is linked to thecorresponding holder 165. The sleeve 171 is formed of a ball-spline andis forced into the casing 168. The compression coil spring 170 isinserted in an annular space surrounded by the casing 168, theshaft-shaped member 169, and the sleeve 171 to support the liquidcontainer 152 and the holder 165 resiliently. According to thisconfiguration, when the liquid level drops due to the liquidconsumption, the weight of the liquid in the liquid container 152 fallsby an equivalent amount, the corresponding liquid holder 165 and liquidcontainer 152 are raised upward by the resilient force of thecompression coil spring 170 by an amount corresponding to thatlightening, and the liquid level is corrected to a constant heightwiseposition with respect to the nozzle heads 8.

Configuring the liquid container elevator mechanism 163 in that mannerstabilizes the liquid pressure in the nozzle heads 8, even when the headportion 43 is raised or lowered. This configuration can reliably preventleakage of liquid from the nozzle heads 8 and reverse-flow of the liquidwithin the nozzle heads 8, and also stabilize the discharge of droplets.Furthermore, since it isn't necessary to provide liquid-level sensors, asimple construction can be simplified.

A locking mechanism 167 is also provided for each of the liquid surfaceposition maintenance mechanisms 166. The locking mechanism 167 is amechanism for ensuring there is no vertical motion in the liquidcontainer 152 and the holder 165 due to the resilience of thecompression coil spring 170 during the vertical motion of the movableframe 162. Each of the liquid surface position maintenance mechanisms166 has a small air cylinder having a rod (not shown in the figures) anda locking pad fixed to the tip end portion of the rod, with the mainbody of the air cylinder being fixed laterally to a side wall in theupper half of the casing 168. The tip end portion of the rod penetratesinto the interior of the casing 168 so that the shaft-shaped member 169can be pressed by the locking pad in order to be locked.

The description now turns to the control system that comprises thecontrol device 13 of the droplet jet patterning device 1, with referenceto FIGS. 38 and 39. Note that the control device 13 is designed tocontrol different devices and mechanisms provided for the droplet jetpatterning device 1.

The host control unit 173 of the control device 13 has a computerincluding a CPU, ROM, and RAM (not shown in the figures). Variouscontrol programs for controlling several motors, the imaging devices,the strobe floodlights, and other various components of the droplet jetpatterning device 1 are stored in the ROM. An operating panel 174, anexternal storage device 175, and power supply 176 are connected to thehost control unit 173. Dot pattern image data to be formed on the glasssubstrate 4, system constants for the droplet jet patterning device 1,and production management information are stored in the external storagedevice 175.

The host control unit 173 is further connected to a digital signalprocessor (DSP) 178, a multi-shaft feed pulse generator circuit 179, amulti-shaft feed pulse generator circuit 180, an output register 181, aninput register 182, an alignment roller 183, a discharge inspectioncontroller 184, and a loader interface 185, through an input-output line177. The DSP 178 is connected to the nozzle heads 8R, 8G, and 8B by asignal output circuit 186 and a drive circuit 187. The DSP 178 has aCPU, ROM, and RAM. A discharge recording control program for driving thenozzle heads 8 to perform discharge recording is stored in the ROM.

The drive circuit 187 has a pulse generation circuit which generatesdrive pulses for driving a large number of nozzle drive piezoelectricelements, and is connected to a waveform monitor 188 for displaying thedrive pulses. The waveforms of the drive pulses can be set in common forthe nozzle heads 8R, 8G, and 8B, or they could be set independently foreach of the nozzle heads 8R, 8G, and 8B.

The DSP 178 is further connected to the multi-shaft feed pulse generatorcircuit 179, the X-axis linear scale 189, and a data storage device 190.The X-axis linear scale 189 is designed to precisely detect the amountof movement of the X-axis slide mechanism 20 that is driven by theX-axis servomotor 28. A detection signal of The X-axis linear scale 189is supplied to the DSP 178 through an amplifier AMP.

The data storage device 190 is designed to store discharge recordingdata and phase data (data that sets the timing for discharge). The datastorage device 190 stores data that has been supplied from the hostcontrol unit 173, and outputs that data to the DSP 178 during thedischarge recording.

Drive circuits 191 to 195 and 197 are connected to the multi-shaft feedpulse generator circuit 179. The drive circuit 191 controls the drivingof the X-axis servomotor 28, based on detection signals from the encoder27 incorporated in the X-axis servomotor 28 and detection signals fromthe X-axis linear scale 189. The drive circuit 192 is connected to theY-axis linear scale 198 for precisely detecting the amount of movementin the Y direction of the Y-axis slide mechanism 19. The drive circuit192 controls the driving of the Y-axis servomotor 31, based on detectionsignals from the encoder 30 incorporated into the Y-axis servomotor 31and detection signals from the Y-axis linear scale 198. According tothis configuration, the X-axis and Y-axis slide mechanism 20 and 19 areused to move the glass substrate 4 precisely in each of the mainscanning direction X and the sub scanning direction Y, to control theposition of the glass substrate 4 precisely in the main scanningdirection X and the sub scanning direction Y.

The drive circuit 193 is designed to drive the rotation servomotor 82,and is connected to an amplifier for amplifying detection signals of theencoder 81 that detects the rotational angle θ. The drive circuit 194 isdesigned to drive the position adjustment servomotor 118 that adjuststhe position in the sub scanning direction Y of the head holders 51G and51B. The drive circuit 195 is designed to drive a Z-axis slideservomotor 410 that causes the nozzle head holder 7 to rise and lower.The drive circuit 197 is designed to drive a Z1-axis slide servomotor196 of the electric cylinder 164 that causes the movable frame 162 torise and lower.

The multi-shaft feed pulse generator circuit 180 is connected to drivecircuits 200, 202, 204, 206, and 207. The drive circuit 200 is designedto control the driving of an alignment adjustment servomotor 199 torotate the glass substrate 4, thereby adjusting the alignment of theglass substrate 4 at the initial setting position. The drive circuits202 and 204 are designed to control the driving of a servomotor 201 formoving the discharge inspection CCD camera and a servomotor 203 formoving the discharge inspection strobe, respectively. The drive circuit206 is designed to control the driving of a servomotor 205 of theelectric cylinder 124 for moving the maintenance mechanism. The drivecircuit 207 is designed to control the driving of the servomotor 137 forthe blotting paper winding of the head maintenance mechanism 123.

As shown in FIG. 39, the output register 181 is connected to a relaycircuit 209. The relay circuit 209 controls a plurality of solenoidvalves 208 that are provided in the valve unit 155 of the liquid supplymechanism 12. The input register 182 is connected to a plurality ofdetection switches through an interface (I/F) 210. The alignmentcontroller 183 is connected to the four CCD cameras 32 a to 32 d, akeyboard, and a monitor 211. The discharge inspection controller 184 isdesigned to control the driving of the CCD camera 142 and the strobefloodlight 143 for discharge inspection. The loader interface 185 isdesigned to transfer signals to and from the external loader H fortransferring the substrate.

The description now turns to the control of the continuous recording todischarge droplets from the three nozzle heads 8R, 8G, and 8B todischarge a dot pattern onto the glass substrate 4, thereby creating apattern such as light-emitting layers on an EL substrate, with referenceto FIGS. 40 to 47. This control is executed by the host control unit173. In the figures, reference symbols Si (where i=1, 2, 3, . . . )denote steps.

As shown in FIG. 40, the continuous recording control is started byoperating a manual switch to turn on the main power source of thedroplet jet patterning device 1. First of all, the nozzle heads 8 areseparated from the rubber pads (caps) 128R, 128G, and 128B of the headmaintenance mechanism 123 to expose the nozzle heads 8 (S1). The hostcontrol unit 173 then checks angle θ and the position of the Z axis ofthe nozzle head holder 7, the position of the substrate receptacle 21along the X and Y axes, and the rotational angle α about the pin 22 asthe axis; causes the glass substrate 4 to move the nozzle heads 8 toθ=0°, the home position (HP) on the Z axis, and the wait position WP onthe X and Y axes. A rotational angle α about the pin 22 is set to be 0°(S2).

In S3, the host control unit 173 determines whether or not the dischargerecording for all the glass substrates 4 (total production) has beencompleted (S3). If it determines that it has been completed (YES at S3),inspection processing A′ is executed in S10, then the processing ends.This inspection processing A′ will be described later. If it isdetermined to not be completed (NO at S3), the host control unit 173determines whether or not the workpiece is the same as the previous one(S4). In this context, “same workpiece” means that the type of the glasssubstrate 4 that is used is the same (all of the dimensions, shape, andalignment marks are the same) and also the dot pattern to be recordedthereon is the same.

If it is determined to be the same (YES at S4), the flow proceeds to S7.If it is determined to not be the same (NO at S4), the flow proceeds toS5, and all of the data relating to discharge recording(discharge-related data) that has been created in the host control unit173 is set in the RAM, the data storage device 190, and other registersof the host control unit 173 (S5). Adjustment processing is done inaccordance with φG and φB that are included within the discharge-relateddata. In this case, φG and φB are rotational angles of the positionadjustment drive mechanism 113. This causes changes of position of thehead holders 51G and 51B by extremely small distances in the subscanning direction Y. In other words, if the position of the G dots andthe B dots with respect to the R dots in the sub scanning direction Yare changed by a small amount, as shown in FIG. 29( c), the head holder51G or 51B can be moved in the sub scanning direction Y. This movementin the sub scanning direction Y can be done by rotating the positionadjustment drive mechanism 113 by just a predetermined angle. When theadjustment processing of S6 ends, the flow proceeds to S7.

In S7, the recording preparation processing A and the inspectionprocessing A′ start simultaneously. In this document, the descriptiondeals with the recording preparation processing A and the inspectionprocessing A′ in sequence.

As shown in FIG. 41, when the recording preparation processing A starts,the feed loader H is used to mount the glass substrate 4 on thesubstrate receptacle 21 at the wait position WP. Then, the glasssubstrate 4 is attracted to the substrate receptacle 21 (S21). Thesubstrate receptacle 21 with the glass substrate 4 mounted thereon isthen moved to an automatic alignment start position by the X-axis andY-axis slide mechanisms 20 and 19 (S22). Correction movement amounts ΔX,ΔY, and Δα are obtained by the Z-axis slide mechanism 6, and positionadjustment by those correction movement amounts is done to set the glasssubstrate 4 at the initial setting position (S23). The glass substrate 4is moved by the X-axis and Y-axis slide mechanisms 20 and 19 so that thereference nozzle is positioned at the recording start point (S24), andprocessing ends.

When the inspection processing A′ starts, a flag is first turned off(S31) and the discharge inspection processing is done (S32). Details ofthis discharge inspection processing will be given later. Historyinformation for the previous glass substrate is added to the memory ofthe host control unit 173 (S33), and the host control unit 173determines whether or not the discharge recording for all the glasssubstrates 4 (total production) has been completed (S34). If itdetermines that it has been completed (YES at S34), the flow proceeds toS42. In S42, the nozzle heads 8R, 8G, and 8B are brought into contactwith the rubber pads 128R, 128G, and 128B to be capped (S42), and theinspection processing A′ ends.

If it is determined that the discharge recording has not been completedfor all the glass substrates 4 (NO at S34), the host control unit 173determines whether or not the discharge status is normal, based on thepreviously executed discharge inspection (S35). If it is determined tobe normal (YES at S35), the flag is set to on (S41) and the inspectionprocessing A′ ends. If it is determined that it was not normal (NO atS35), the host control unit 173 determines whether or not purgeprocessing has been executed a predetermined number of times (S36). Ifit is determined that the purge processing has not been executed thepredetermined number of times (NO at S36), the purge processing and thewiping processing are executed (S37), discharge inspection processingsimilar to that of S32 is then executed (S38), and the flow proceeds toS35.

If it is determined that the purge processing has been executed thepredetermined number of times (YES at S36), it is determined thatrecording is not possible with the current nozzles 55. And the hostcontrol unit 173 then determines whether or not discharge recording canbe possible with substitute nozzles (S39). If it is determined to bepossible (YES at S39), the flag is set to on (S41), and the inspectionprocessing A′ is over. If it is determined to be not possible (NO atS39), continuous recording suspension processing is executed (S40), andthe inspection processing A′ ends. In this case, the flag remains set tooff.

As shown in FIG. 40, after S7, the host control unit 173 determineswhether or not the recording preparation processing A and the inspectionprocessing A′ have been completed (S8). If it is determined that one orboth of the processes A and A′ has not ended (NO at S8), the hostcontrol unit 173 waits until both of them have ended. If both of themhave ended (YES at S8), the host control unit 173 determines whether ornot the flag is on (S9). If it determines that the flag is not on (NO atS9), the processing ends. If it determines that the flag is on, on theother hand (YES at S9), the flow proceeds to S51 of FIG. 43.

At S51, the Z-axis slide mechanism 6 is used to lower the head portion43 to the discharge position DP (S51). The four-bar linkage 49 is thenrotated aslant if necessary, based on the rotational angle θ that hasbeen input and set (S52). If the results of the previous dischargeinspection are normal (YES at S53), the regular recording, that is, theformation of a pattern while the glass substrate 4 is moved relative tothe head portion 43 in the main scanning direction X and the subscanning direction Y, is performed (S54) and the flow proceeds to S55.

If the results of the discharge inspection determine that the dischargeis abnormal, on the other hand (NO at S53), skipped nozzle recording isperformed (S56). This skipped nozzle recording is recording in a statein which some of the nozzles 55 are suspended. One example of theskipped nozzle recording is one stage of interlace recording in whichonly the odd-numbered nozzles operate in one pass of recording. Data forsubstitute nozzle recording is then created and stored in a page memoryof the data storage device 190 or other types of registers (S57). Thesubstitute nozzle recording is then executed (S58) and the flow proceedsto S55. The substitute nozzle recording is that when No. 1 and No. 2nozzles are not available, No. 3 and No. 4 nozzles are used again torecord on the glass substrate 4 that has already been recorded upon,without using nozzles No. 1 and No. 2.

At S55, history information for that glass substrate 4 is stored inmemory of the host control unit 173 (S55), and the home position returnprocessing and the wait position return processing start simultaneously(S59). As shown in FIG. 44, the home position return processing firstreturns the rotational angle θ of the four-bar linkage 49 to 0 degrees(S61), then raising the nozzle head holder 7 to the home position HP(S62), whereupon the processing ends. The wait position returnprocessing causes the substrate receptacle 21 and the glass substrate 4to move to the wait position WP (S63), then uses the substrate liftmechanism 23 to raise the glass substrate 4 by a predetermined smalldistance from the substrate receptacle 21 and transfer the raisedsubstrate 4 to the feed loader H (S64). The values of ΔX, ΔY, and Δαthat were adjusted in S23 are returned to their original values (S65)and processing ends.

In FIG. 43, after S59, the host control unit 173 determines in S60whether or not the home position return processing and the wait positionreturn processing have ended. If at least one of them has not ended (NOat S60), the host control unit 173 waits until the processing has ended.If both have ended (YES at S60), the flow returns to S3 of FIG. 40.

The description now turns to the discharge inspection processingexecuted in S32 and S38, with reference to the flowchart of FIG. 46.When this processing starts, the host control unit 173 first determineswhether or not the nozzle head holder 7 is at the inspection/adjustmentposition UP (S70). If the nozzle head holder 7 is not at theinspection/adjustment position UP (NO at S70), the nozzle head holder 7is moved by the Z-axis slide mechanism 6 to the inspection/adjustmentposition UP (S71), and the flow proceeds to S72. If the nozzle headholder 7 is at the inspection/adjustment position UP (YES at S70), theflow proceeds to S72 without executing S71. At S72, the host controlunit 173 determines whether or not the head maintenance mechanism 123 isat the inspection position (S72). If it is not at the inspectionposition, (NO at S72), the head maintenance mechanism 123 is moved tothe inspection position (S73) and the flow proceeds to S74. If the headmaintenance mechanism 123 is at the inspection position (YES at S72),the flow proceeds directly to S74.

At S74, discharge inspection of the nozzle head 8R is performed and inthe subsequent S75 and S76 discharge inspection is performed for each ofthe nozzle heads 8G and 8B (S75 and S76). The CCD camera 142 and thestrobe floodlight 143 are then moved to their predetermined standbypositions (S77), and the head maintenance mechanism 123 is moved to itspredetermined standby position (S78). This completes the dischargeinspection processing.

The description now turns to the discharge inspection of the nozzle head8R that is performed in S74. Note that the discharge inspection is thesame for all of the nozzle heads 8R, 8G, and 8B, therefore, only thedischarge inspection of the nozzle head 8B is described here, based onthe flowchart of FIG. 47, and description of the discharge inspection ofthe nozzle heads 8G and 8B performed in S75 and S76 is omitted.

In FIG. 47, when the processing starts, first a counter i is set to 1(S80) and a position Ri is set in an imaging position register (S81).The CCD camera 142 is then moved to the position Ri and the strobefloodlight 143 is also moved to the position Ri (S82). A dischargeinstruction is then output to the i-th group of 16 nozzles 55 of thenozzle head 8R (S83). Accordingly, 16 target nozzles 15 discharge adroplet, respectively. Note that the position Ri is the positioncorresponding to the i-th group of nozzles.

A timer T1 and a timer T2 are then started (S84). At S85, the hostcontrol unit 173 determines whether or not the timer T1 has measured apredetermined time α, if the timer T1 has not yet measured that time (NOat S85), the host control unit 173 waits until the timer T1 measures thetime α. If the timer T1 has measured that time (YES at S85), the hostcontrol unit 173 instructs the shutter operation of the CCD camera 142(S86). The host control unit 173 then determines whether or not thetimer T2 has measured a predetermined time β (S87). If timer T2 has notyet measured that time (NO at S87), the host control unit 173 waitsuntil the timer T2 measures the time A. If the timer T2 has measuredthat time (YES at S87), the host control unit 173 instructs theoperation of the strobe floodlight 143 (S88). Thus the droplets thathave been discharged from the 16 nozzles 55 are imaged. Note that thepredetermined times α and β times are very short times that aresubstantially equal, so that the strobe lighting and the shutteroperation are substantially simultaneous.

The host control unit 173 then executes image processing on image dataof the image of the captured droplets, to determine whether thedischarge is normal or abnormal, and posts the result on a display ofthe operating panel 174 (S89). At this time, each of the nozzles 55 isdetermined to be normal if the image of the droplets is within theobservation window 151 of the CCD camera 142. The nozzles 55 aredetermined abnormal if the image is outside of the windows (see FIGS. 31and 32). The host control unit 173 then increments the counter i by 1(S90) and determines whether or not the imaging of the fourth group ofnozzles has been completed (S91). If it has not been completed (NO atS91), the flow returns to S82 and the same processing is executed insequence up until the fourth group. If the fourth group has beencompleted (YES at S91), the processing ends.

In this manner, since the inspection processing A′ can be executed bythe discharge inspection mechanism 121 during the execution of therecording preparation processing A that moves the glass substrate 4(S22) and performs automatic alignment (S23), it is possible to increasethe operating efficiency of the droplet jet patterning device 1 and alsoreduce the occurrence of defective products (defective EL substrates)due to discharge errors.

As described above, the present invention relates to the nozzle headholder 7 which is provided with the four-bar linkage 49, the pair ofrotational pivots 50A and 50B, and the head holders 51 each having twoends that are connected in a rotatable manner to the pair of first linkmembers 56A and 56B. Accordingly, the nozzle head holder 7 can bereadily attached to and removed from the external head assemblyattachment stand 25 that supports the nozzle head holder 7. It istherefore possible to simplify the configuration for attaching andremoving the nozzle heads 8 for repair and replacement, thus ensuringmaintainability.

Since the rotational pivot 50A is provided at an intermediate portion ofthe second link members 57A and 57B, the reference nozzles (such as theNo. 1 nozzle) of the nozzle heads 8 can be positioned on the line BFthat links the centers of the rotational pivots 50A and 50B. Even if thenozzle heads 8 are rotated, the position of the reference nozzle is notchanged, or even if the positions of the nozzles are changed, the amountof the change is so small. Accordingly, it is possible not only tosimplify the data processing for calculating the drive data androtational angle for causing relative movements between the glasssubstrate 4 and the nozzle heads 8, but also to increase the precisionof the pattern formation.

In addition, since the plurality of nozzle heads 8R, 8G, and 8B aredisposed at a predetermined spacing in the main scanning direction X,these nozzle heads 8R, 8G, and 8B can be inclined with respect to thesub scanning direction Y to set the discharge pitch in the sub scanningdirection Y to a desired value for recording the pattern, so that thenozzle heads 8R, 8G, and 8B are applicable to the manufacture of colorfilters or EL substrates for organic color EL displays. Moreover, sincethese nozzle heads 8 includes nozzle heads that discharge droplets of aplurality of different colors for forming an EL light-emitting layer,the throughput can be increased and it becomes possible to manufactureEL substrates for full-color use. In addition, use of the nozzle headholder 7 also makes it possible to discharge and record a hole transportlayer from these nozzle heads 8.

Note that if advances in technology make it possible to mix a holetransport component and an EL light-emitting component within a singledroplet, and thus obtain light emission from a single layer, it is notnecessary to form a hole transport layer.

The nozzle heads 8G and 8B move only in the sub scanning direction Y butdo not move in the main scanning direction X, even when the nozzle heads8G and 8B are rotated aslant with respect to the sub scanning directionY. Accordingly, the nozzle heads 8G and 8B can be moved by small amountsin the sub scanning direction Y alone via the paired roller members 102and guide surfaces 104, making it possible to adjust the position of thenozzle heads 8 finely in the sub scanning direction Y accurately,efficiently, and automatically. In addition, since the pair of rollermembers 102 are each positioned at predetermined positions with respectto the pair of first link members 56A and 56B, irrespective of therotation angle of the nozzle heads 8. Accordingly, the movementmechanisms 53A and 53B can be mounted at predetermined positions of thefirst link members 56A and 56B. And actuators for moving these movementmechanisms 53A and 53B can be provided externally, so that fineadjustment of the nozzle heads 8 in the sub scanning direction Y can beautomated.

The pattern processing stage 120 is disposed in the first-floor (lowerside) patterning room 15, the inspection/adjustment stage 44 is disposedin the second-floor (upper side) maintenance room 16, and the headportion 43 can be raised and lowered between these two stages throughthe aperture portion 14 a. Accordingly, the head portion 43 can be movedto the inspection/adjustment position UP where discharge inspection canbe performed on the nozzles 55, during an idle period such as when thedischarge formation processing is halted. After the dischargeinspection, the head portion 43 can be moved immediately back to thedischarge position DP and the discharge formation processing can beresumed. Since discharge inspection during a processing halt in thedischarge formation processing step can be performed, it is possible toreduce the occurrence of defective products and improve the operatingefficiency of the droplet jet patterning device 1. Since the two stagesare disposed in a vertical spatial arrangement, the usage efficiency ofthe space within the droplet jet patterning device 1 can be increasedand the device can be made more compact, which is beneficial from theinstallation cost point of view. Moreover, since the horizontalpartitioning plate 14 substantially separates the upper and lower partsof the device 1, foreign bodies such as dust and debris do not fall ontothe glass substrate 4 held on the substrate receptacle 21, even when amovable member is moved higher than the horizontal partitioning plate14, making it possible to prevent the occurrence of defective products.

The pattern formation can be done by mounting and holding the glasssubstrate 4 on the substrate receptacle 21 and moving the glasssubstrate 4 relative to the nozzle heads 8 in both the main scanningdirection X and the sub scanning direction Y.

In other words, since the medium transfer mechanism 24 is provided formoving the glass substrate 4 in each of the main scanning direction Xand the sub scanning direction Y, it is not necessary to move the headportion 43 in either the main scanning direction X or the sub scanningdirection Y to form the pattern. For that reason, the configuration forraising and lowering the head portion 43 by the Z-axis slide mechanism 6be simplified. Accordingly, switching of the position of the headportion 43 by the Z-axis slide mechanism 6 can be performed between thespace below the horizontal partitioning plate 14 and the spacethereabove. It is possible to perform pattern formation and dischargeinspection efficiently by providing the discharge inspection mechanism121 for inspecting the discharge status of the plurality of nozzles 55on the inspection/adjustment stage 44 and raising and lowering the headportion 43 by the Z-axis slide mechanism 6.

The nozzle heads 8 are fixed to the head holder 51. The two ends of thehead holder 51 and the pair of first link members 56A and 56B areconnected together in a rotatable and also removable manner by theroller members 102 acting as pins, and these roller members 102 extendin a direction perpendicular to the head surface of the nozzle heads 8.According to the above configuration, the head body 500 can besimplified. Use of the rotatable roller members 102 as connecting pinsis preferable, from the point of view of smoothing the rotation and themovement in the sub scanning direction Y of the head body 500. However,the connecting pins need not be restricted to the roller members 102.

The head body 500 provided with a plurality of nozzle heads 8 isattached rotatably and also removably to the first link members 56A and56B of the four-bar linkage 49. Accordingly, this four-bar linkage 49 isattached to the head assembly attachment stand 25. Thus, the distancebetween the discharge-target medium and the head body 500 can bemaintained extremely precisely. For that reason, the RGB light-emittinglayers can be arrayed on the substrate to an extremely high precision.Since no play occurs in the movable portions between the head body 500and the first link members 56A and 56B, it is possible to create an ELdisplay in a simpler manner, in a shorter time, and at a lower cost thanwith a conventional screen-printing method.

The embodiment of the present invention is described above, however,various modifications and variations are included within the scope ofthe present invention. Thus the scope of the present invention must becomprehended by the claims herein, in addition to the above embodiment.

For example, the embodiment above was described as relating to a dropletjet patterning device that forms a dot pattern on a glass substrate fora color EL display. However, the present invention can also be appliedto other applications. For instance, the present invention can beapplied to the formation of a dot pattern during the manufacture of acolor filter for a color LCD, or a large-scale inkjet printer, or adroplet jet patterning device for another application.

In addition, the output shaft of the motor 82 that causes the four-barlinkage 49 to pivot can be connected directly to the pin member 75 ofthe rotational pivot 50B, to pivot the four-bar linkage 49. Furthermore,means for moving and driving the front-side first link member 56Aprecisely to the left or means for moving and driving the rear-sidefirst link member 56B to the right can be utilized as the means forpivoting the four-bar linkage 49. An electric cylinder or a solenoidactuator can be used as the above means.

The means for detecting the rotational angle of the four-bar linkage 49is not limited to the previously-described encoder 81. For example, anencoder may be provided in a coaxial with and above the left-siderotational pivot 50A to detect the rotational angle of the second linkmember 57A. Similarly, a highly precise servomotor may be used as themotor 82 for rotation of the nozzle holder. Accordingly, the detectionof the inclination rotational angle of the four-bar linkage 49 is basedon signals from an encoder of that servomotor.

It is necessary to provide the pair of rotational pivots 50A and 50B ofthe four-bar linkage 49 at intermediate positions of the pair of secondlink members 57A and 57B (intermediate positions between the pair offirst link members 56A and 56B). However, it is also possible to providethe pair of rotational pivots 50A and 50B at substantially centralportions in the sub scanning direction Y of the pair of second linkmembers 57A and 57B, and to position a predetermined numbered nozzle atsubstantially the central position of the nozzle array of the referencenozzle head 8R on a surface that links the pair of rotational pivots 50Aand 50B.

The pair of rotational pivots 50A and 50B of the four-bar linkage 49 areprovided mainly on the pin members 75 that are fixed to the second linkmembers 57A and 57B. However, a pair of pin members fixed to the framemember 46 side can be fitted in a freely sliding manner in a pair ofholes formed in the second link members 57A and 57B. In this case, thepair of holes formed the second link members 57A and 57B act as the pairof rotational pivots.

The relative movement generation means is not limited to the mediumtransfer mechanism 24. Any suitable means of generating relativemovement between the nozzle heads and the discharge-target medium in theX and Y directions (the main scanning direction X and the sub scanningdirection Y) can be used as the relative movement generation means. Forexample, the nozzle heads 8 may be moved in the main scanning directionX, and the substrate receptacle 21 may be moved in the sub scanningdirection Y.

Furthermore, the head holder 51R may be supported to be freely movablein the sub scanning direction Y, in the same manner as the other headholders 51G and 51B.

The nozzle head holder 7 need not be removable. The nozzle head holder 7can also be provided integrally with the droplet jet patterning device1.

1. A nozzle head holder (7) for holding a plurality of nozzle heads(500) having a plurality of nozzles (55) formed therein, the pluralityof nozzle heads being disposed at a predetermined spacing in a mainscanning direction (X), the nozzle head holder (7) comprising: afour-bar linkage (49) having a pair of first link members (56A and 56B)that extend parallel to the main scanning direction (X) and a pair ofsecond link members (57A and 57B) that connect together said pair offirst link members (56A and 56B); and movement means (53A and 53B) formoving at least one nozzle head of said plurality of nozzle heads (500)parallel to a sub scanning direction (Y) that is perpendicular to themain scanning direction (X); wherein: each of said nozzle heads (500)has two end portions connected to said pair of first link members (56Aand 56B); and said movement means (53A and 53B) moves said at least oneof said nozzle heads parallel in the sub scanning direction (Y),relative to the pair of first link members (56A and 56B).
 2. The nozzlehead holder (7) as defined by claim 1, wherein: concavities (103A and103B) having guide surfaces (104A and 104B) are formed in said pair offirst link members (56A and 56B), respectively; said movement means (53Aand 53B) includes a pair of roller members (102A and 102B) that areprovided rotatably on the two end portions of said at least one of saidnozzle heads, and pressure members (105A and 105B) that press the rollermembers (102A and 102B) against said guide surfaces (104A and 104B); andsaid pressure members (105A and 105B) are moved parallel to the subscanning direction (Y) along the guide surfaces (104A and 104B), whilepressing the roller members (102A and 102B) against the guide surfaces(104A and 104B).
 3. The nozzle head holder (7) as defined by claim 1,wherein said plurality of nozzle heads (500) are installed removably onsaid pair of first link members (56A and 56B).
 4. The nozzle head holder(7) as defined by claim 1, wherein the two end portions of each of saidnozzle heads (500) are urged by a resilient member (110) so as to be insurface-contact with upper surfaces of the first link members (56A and56B).
 5. The nozzle head holder (7) as defined by claim 1, wherein eachof said nozzle heads (500) includes a nozzle portion (8) having aplurality of nozzles (55) formed therein, and a head holder (51) forsupporting said nozzle portion (8), and the two end portions of saidhead holder (51) are connected to said pair of first link members (56Aand 56B).
 6. A nozzle head (500) characterized in being used in thenozzle head holder (7) as defined by claim
 1. 7. A droplet jetpatterning device (1) comprising: the nozzle head holder (7) as definedby claim 1; a head assembly attachment stand (25) for installing saidnozzle head holder (7) in a removable manner; a medium holder means (21)for holding a discharge-target medium (4); a relative movementgeneration means for moving said discharge-target medium (4) in a mainscanning direction (X) and in a sub scanning direction (Y) relative tosaid nozzle head (500); pivoting means (80) for pivoting said four-barlinkage (49); and rotational pivots (50A and 50B) provided at anintermediate points of said pair of second link members (57A and 57B),respectively; wherein: said pair of second link members (57A and 57B)are capable of rotating about said rotational pivots (50A and 50B); saidnozzle head (500) are connected rotatably to said pair of first linkmembers (56A and 56B); and said pivoting means (80) rotates said pair ofsecond link members (57A and 57B) about said rotational pivots (50A and50B) to pivot said four-bar linkage (49).
 8. The droplet jet patterningdevice (1) as defined by claim 7, further comprising a movement drivemeans (113) connected removably to said movement means (53A and 53B) fordriving said movement means (53A and 53B) to move at least one nozzlehead parallel to the sub scanning direction (Y).
 9. The droplet jetpatterning device (1) as defined by claim 7, further comprising pivotingamount detection means (81) for detecting the pivoting amount of thefour-bar linkage (49), and pivoting amount control means (13) forcontrolling said pivoting means (80) based on the detected pivotingamount.